Geography - note

Afghanistan

landlocked; the Hindu Kush mountains that run northeast to southwest divide the northern provinces from the rest of the country; the highest peaks are in the northern Vakhan (Wakhan Corridor)

Akrotiri and Dhekelia

British extraterritorial rights also extended to several small off-post sites scattered across Cyprus; of the Sovereign Base Area land, 60% is privately owned and farmed, 20% is owned by the UK Ministry of Defense, and 20% is SBA Crown land

Albania

strategic location along Strait of Otranto (links Adriatic Sea to Ionian Sea and Mediterranean Sea)

Algeria

largest country in Africa but 80% desert; canyons and caves in the southern Hoggar Mountains and in the barren Tassili n'Ajjer area in the southeast of the country contain numerous examples of prehistoric art -- rock paintings and carvings depicting human activities and wild and domestic animals (elephants, giraffes, cattle) -- that date to the African Humid Period, roughly 5,000 to 11,000 years ago, when the region was completely vegetated

American Samoa

Pago Pago has one of the best natural deepwater harbors in the South Pacific Ocean, sheltered by shape from rough seas and protected by peripheral mountains from high winds; strategic location in the South Pacific Ocean

Andorra

landlocked; straddles a number of important crossroads in the Pyrenees

Angola

the province of Cabinda is an exclave, separated from the rest of the country by the Democratic Republic of the Congo

Anguilla

the most northerly of the Leeward Islands in the Lesser Antilles

Antarctica

the coldest, windiest, highest (on average), and driest continent; during the summer, more solar radiation reaches the surface at the South Pole than is received at the equator in an equivalent period

mostly uninhabitable, 99% of the land area is covered by the Antarctic ice sheet, the largest single mass of ice on Earth; it covers an area of 14 million sq km (5.4 million sq mi) and contains 26.5 million cu km (6.4 million cu mi) of ice (almost 62% of the world's fresh water)

Antigua and Barbuda

Antigua has a deeply indented shoreline with many natural harbors and beaches; Barbuda has a large western harbor

Arctic Ocean

major chokepoint is the southern Chukchi Sea (northern access to the Pacific Ocean via the Bering Strait); strategic location between North America and Russia; shortest marine link between the extremes of eastern and western Russia; floating research stations operated by the US and Russia; maximum snow cover in March or April about 20 to 50 centimeters over the frozen ocean; snow cover lasts about 10 months

Argentina

second-largest country in South America (after Brazil); strategic location relative to sea lanes between the South Atlantic and the South Pacific Oceans (Strait of Magellan, Beagle Channel, Drake Passage); diverse geophysical landscapes range from tropical climates in the north to tundra in the far south; Cerro Aconcagua is the Western Hemisphere's tallest mountain, while Laguna del Carbón is the lowest point in the Western Hemisphere; shares Iguazú Falls, the world's largest waterfalls system, with Brazil

Armenia

landlocked in the Lesser Caucasus Mountains; Sevana Lich (Lake Sevan) is the largest lake in this mountain range

Aruba

a flat, riverless island known for its white sand beaches; its tropical climate is moderated by constant trade winds from the Atlantic Ocean; the temperature is almost constant at about 27 degrees Celsius (81 degrees Fahrenheit)

Ashmore and Cartier Islands

Ashmore Reef National Nature Reserve established in 1983; Cartier Island Marine Reserve established in 2000

Atlantic Ocean

major chokepoints include the Dardanelles, Strait of Gibraltar, access to the Panama and Suez Canals; strategic straits include the Strait of Dover, Straits of Florida, Mona Passage, The Sound (Oresund), and Windward Passage; the equator divides the Atlantic Ocean into the North Atlantic Ocean and South Atlantic Ocean

Australia

note 1: world's smallest continent but sixth-largest country; the largest country in Oceania, the largest country entirely in the Southern Hemisphere, and the largest country without land borders

note 2: the Great Dividing Range that runs along eastern Australia is that continent’s longest mountain range and the third-longest land-based range in the world; the term "Great Dividing Range" refers to the fact that the mountains form a watershed crest from which all of the rivers of eastern Australia flow – east, west, north, and south

note 3: Australia is the only continent without glaciers; it is the driest inhabited continent on earth; Perth on the west coast is home to the invigorating sea breeze known as the "Fremantle Doctor," one of the most consistent winds in the world; Australia hosts 10% of the world's biodiversity, and a great number of its flora and fauna exist nowhere else in the world

Austria

note 1: landlocked; strategic location at the crossroads of central Europe with many easily traversable Alpine passes and valleys; major river is the Danube; population is concentrated on eastern lowlands because of steep slopes, poor soils, and low temperatures elsewhere

note 2: the world's largest and longest ice cave system at 42 km (26 mi) is the Eisriesenwelt (Ice Giants World) inside the Hochkogel mountain near Werfen, about 40 km south of Salzburg; ice caves are bedrock caves that contain year-round ice formations; they differ from glacial caves, which are transient and are formed by melting ice and flowing water within and under glaciers

Azerbaijan

both the main area of the country and the Naxcivan exclave are landlocked

Bahamas, The

strategic location adjacent to US and Cuba; extensive island chain of which 30 are inhabited

Bahrain

close to primary Middle Eastern petroleum sources; strategic location in Persian Gulf, through which much of the Western world's petroleum must transit to reach open ocean

Bangladesh

most of the country is situated on deltas of large rivers flowing from the Himalayas: the Ganges unites with the Jamuna (main channel of the Brahmaputra) and later joins the Meghna to eventually empty into the Bay of Bengal

Barbados

easternmost Caribbean island

Belarus

landlocked; glacial scouring accounts for the flatness of Belarusian terrain and for its 11,000 lakes

Belgium

crossroads of Western Europe; most West European capitals are within 1,000 km of Brussels, the seat of both the EU and NATO

Belize

only country in Central America without a coastline on the North Pacific Ocean

Benin

sandbanks create difficult access to a coast with no natural harbors, river mouths, or islands

Bermuda

the archipelago consists of over 170 coral islands and islets with ample rainfall, as well as thousands of cays, but no rivers or freshwater lakes; some land was leased by the US Government from 1941 to 1995

Bhutan

landlocked; strategic location between China and India; controls several key Himalayan mountain passes

Bolivia

landlocked; shares control of Lago Titicaca, world's highest navigable lake (elevation 3,805 m), with Peru

Bosnia and Herzegovina

within Bosnia and Herzegovina's recognized borders, the country is divided into a joint Bosniak/Croat Federation (about 51% of the territory) and the Bosnian Serb-led Republika Srpska or RS (about 49% of the territory); the region called Herzegovina is contiguous to Croatia and Montenegro

Botswana

landlocked; sparsely populated with most settlement concentrated in the southern and eastern parts of the country; geography dominated by the Kalahari Desert, which covers about 70% of the country, although the Okavango Delta brings considerable biodiversity as one of the largest inland deltas in the World 

Bouvet Island

almost entirely covered by glacial ice (93%); declared a nature reserve by Norway; the distance from Bouvet Island to Norway is 12,776 km, which is almost one-third the circumference of the earth

Brazil

note 1: largest country in South America and in the Southern Hemisphere; shares common boundaries with every South American country except Chile and Ecuador; most of the Pantanal, the world's largest tropical wetland, extends through the west central part of the country; shares Iguaçu Falls (Iguazú Falls), the world's largest waterfalls system, with Argentina

note 2: Rocas Atoll, located off the northeast coast of Brazil, is the only atoll in the South Atlantic

British Indian Ocean Territory

note 1: archipelago of 55 islands; Diego Garcia, the largest and southernmost island, occupies a strategic location in the central Indian Ocean

note 2: Diego Garcia is the only inhabited island of the BIOT

British Virgin Islands

strong ties to nearby US Virgin Islands and Puerto Rico

Brunei

close to vital sea lanes through South China Sea linking Indian and Pacific Oceans; two parts physically separated by Malaysia; the eastern part, the Temburong district, is an exclave and is almost an enclave within Malaysia

Bulgaria

strategic location near Turkish Straits; controls key land routes from Europe to Middle East and Asia

Burkina Faso

landlocked savanna cut by the three principal rivers, the Black, Red, and White Voltas

Burma

strategic location near major Indian Ocean shipping lanes; the north-south flowing Irrawaddy River is the country's largest and most important commercial waterway

Burundi

landlocked; straddles crest of the Nile-Congo watershed; the Kagera, which drains into Lake Victoria, is the most remote headstream of the White Nile

Cabo Verde

strategic location 500 km from west coast of Africa near major north-south sea routes; one of four North Atlantic archipelagos that make up Macaronesia; the others are Azores (Portugal), Canary Islands (Spain), and Madeira (Portugal)

Cambodia

a land of paddies and forests dominated by the Mekong River and Tonle Sap (Southeast Asia's largest freshwater lake)

Cameroon

sometimes referred to as the hinge of Africa because of its central location on the continent and its position at the west-south juncture of the Gulf of Guinea; areas of thermal springs and indications of current or prior volcanic activity; Mount Cameroon, the highest mountain in Sub-Saharan west Africa, is an active volcano

Canada

note 1: second-largest country in the world (after Russia) and largest in the Americas; strategic location between Russia and US via north polar route; approximately 90% of the population is concentrated within 160 km (100 mi) of the US border

note 2: Canada has more fresh water than any other country, and almost 9% of Canadian territory is water; Canada has at least 2 million and possibly over 3 million lakes, more than all other countries combined

Cayman Islands

important location between Cuba and Central America

Central African Republic

landlocked; almost the precise center of Africa

Chad

note 1: Chad is the largest of Africa's 16 landlocked countries

note 2: a wide variety of animals lived in modern-day Chad during the African Humid Period, including elephants, giraffes, hippos, and antelope; the last remnant of this "Green Sahara" exists in the Lakes of Ounianga in northern Chad, a series of 18 interconnected freshwater, saline, and hypersaline lakes 

note 3: Lake Chad, the most significant water body in the Sahel, is a remnant of a former inland sea, paleolake Mega-Chad; at its greatest extent, sometime before 5000 B.C., Lake Mega-Chad was the largest of four Saharan paleolakes that existed during the African Humid Period; it covered an area of about 400,000 sq km (150,000 sq mi), roughly the size of today's Caspian Sea

Chile

note 1: Chile is the longest country north-to-south in the world, extending across 39 degrees of latitude

note 2: Chile is one of the countries along the Ring of Fire, which is a belt bordering the Pacific Ocean that contains about 75% of the world's volcanoes and up to 90% of the world's earthquakes

note 3: the Atacama Desert in the north of Chile is the driest desert in the world; Ojos del Salado (6,893 m) in the Atacama Desert is the highest active volcano in the world, Chile's tallest mountain, and the second-highest in the Western Hemisphere and the Southern Hemisphere; the volcano's small crater lake is the world's highest lake at 6,390 m

China

note 1: world's fourth largest country (after Russia, Canada, and the US) and largest country situated entirely in Asia; Mount Everest, on the border with Nepal, is the world's tallest peak above sea level

note 2: the largest cave chamber in the world is the Miao Room, in the Gebihe cave system at China's Ziyun Getu He Chuandong National Park, which encloses about 10.78 million cu m (380.7 million cu ft); the world's largest sinkhole is the Xiaoxhai Tiankeng sinkhole in Chongqing Municipality, which is 660 m deep, with a volume of 130 million cu m

Christmas Island

located along major sea lanes of the Indian Ocean

Clipperton Island

the atoll reef is approximately 12 km (7.5 mi) in circumference

Cocos (Keeling) Islands

there are 27 coral islands in the group; apart from North Keeling Island, which lies 30 km north of the main group, the islands form a horseshoe-shaped atoll around a lagoon

Colombia

only South American country with coastlines on both the North Pacific Ocean and Caribbean Sea

Comoros

important location at northern end of Mozambique Channel; the only Arab League country that lies entirely in the Southern Hemisphere

Congo, Democratic Republic of the

note 1: second-largest country in Africa (after Algeria) and largest country in sub-Saharan Africa; straddles the equator; dense tropical rainforest in central river basin and eastern highlands; the narrow strip of land that controls the lower Congo River is the DRC's only outlet to the South Atlantic Ocean

note 2: the Congo River, most of which flows through the DRC, has never been accurately measured along much of its length because of its speed, cataracts, rapids, and turbulence; nonetheless, it is conceded to be the deepest river in the world, with estimates of the point of greatest depth varying between 220 and 250 meters

Congo, Republic of the

about 70% of the population lives in Brazzaville, Pointe-Noire, or along the railroad between them

Cook Islands

the northern Cook Islands are seven low-lying, sparsely populated, coral atolls; the southern Cook Islands, where most of the population lives, consist of eight elevated, fertile, volcanic isles, including the largest, Rarotonga, at 67 sq km

Coral Sea Islands

important nesting area for birds and turtles

Costa Rica

four volcanoes, two of them active, rise near the capital of San Jose in the center of the country; one of the volcanoes, Irazu, erupted destructively in 1963-65

Cote d'Ivoire

most of the inhabitants live along the sandy coastal region; apart from the capital area, the forested interior is sparsely populated

Croatia

controls most land routes from Western Europe to the Aegean Sea and Turkish Straits; most Adriatic Sea islands lie off the coast of Croatia -- some 1,200 islands, islets, ridges, and rocks

Cuba

largest country in Caribbean and westernmost island of the Greater Antilles

Curacao

Curaçao is a part of the Windward Islands (southern) group in the Lesser Antilles

Cyprus

the third largest island in the Mediterranean Sea (after Sicily and Sardinia)

Czechia

note 1: landlocked; strategically located on some of oldest and most significant land routes in Europe; Moravian Gate is a traditional military corridor between the North European Plain and the Danube in central Europe

note 2: the Hranice Abyss in Czechia is the world's deepest surveyed freshwater cave at 519 m (1,703 ft); its survey is not complete, and it may be up to 800-1,200 m (2,625-3,937 ft) deep

Denmark

composed of the Jutland Peninsula and a group of more than 400 islands (Danish Archipelago); controls Danish Straits (Skagerrak and Kattegat) linking Baltic and North Seas; about one-quarter of the population lives in greater Copenhagen

Djibouti

strategic location near world's busiest shipping lanes and close to Arabian oilfields; Lac Assal (Lake Assal) is the lowest point in Africa and the saltiest lake in the world

Dominica

known as "The Nature Island of the Caribbean" due to its lush and varied flora and fauna, which are protected by an extensive natural park system; the most mountainous of the Lesser Antilles, its volcanic peaks are cones of lava craters and include Boiling Lake, the second-largest thermally active lake in the world

Dominican Republic

shares island of Hispaniola with Haiti (eastern two-thirds makes up the Dominican Republic, western one-third is Haiti); the second largest country in the Antilles (after Cuba); geographically diverse with the Caribbean's tallest mountain, Pico Duarte, and lowest elevation and largest lake, Lago Enriquillo

Ecuador

Cotopaxi in the Andes is highest active volcano in world

Egypt

controls Sinai Peninsula, the only land bridge between Africa and remainder of Eastern Hemisphere; controls Suez Canal, a sea link between Indian Ocean and Mediterranean Sea

El Salvador

smallest Central American country and only one without a coastline on the Caribbean Sea

Equatorial Guinea

insular and continental regions widely separated; despite its name, no part of the equator passes through Equatorial Guinea -- the mainland part of the country is located just north of the equator

Eritrea

strategic geopolitical position along world's busiest shipping lanes

Estonia

the mainland terrain is flat, boggy, and partly wooded; over 1,500 islands lie offshore

Eswatini

landlocked; almost completely surrounded by South Africa

Ethiopia

the most populous landlocked country in the world; the Blue Nile, the chief headstream of the Nile by water volume, rises in T'ana Hayk (Lake Tana) in northwest Ethiopia

Falkland Islands (Islas Malvinas)

deeply indented coast provides good natural harbors; short growing season

Faroe Islands

archipelago of 17 inhabited islands, one uninhabited island, and a few uninhabited islets; strategically located along important sea lanes in northeastern Atlantic; precipitous terrain limits habitation to small coastal lowlands

Fiji

consists of 332 islands, approximately 110 of which are inhabited, and more than 500 islets

Finland

long boundary with Russia; Helsinki is northernmost national capital on European continent; population concentrated on small southwestern coastal plain

France

largest Western European nation; most major French rivers -- the Meuse, Seine, Loire, Charente, Dordogne, and Garonne -- flow northward or westward into the Atlantic Ocean, only the Rhone flows southward into the Mediterranean Sea

French Polynesia

includes five archipelagoes: four volcanic (Iles Gambier, Iles Marquises, Iles Tubuai, Society Islands) and one coral (Archipel des Tuamotu); the Tuamotu Archipelago forms the largest group of atolls in the world -- 78 in total, 48 inhabited; Makatea in the Tuamotu Archipelago is one of the three great phosphate rock islands in the Pacific Ocean -- the others are Banaba (Ocean Island) in Kiribati and Nauru

French Southern and Antarctic Lands

islands are widely scattered across remote locations in the southern Indian Ocean

Bassas da India (Iles Éparses): atoll is a circular reef on top of a long-extinct, submerged volcano

Europa Island and Juan de Nova Island (Iles Éparses): wildlife sanctuary for seabirds and sea turtles

Glorioso Island (Iles Éparses): an extensive reef system surrounds the island

Tromelin Island (Iles Éparses): climatologically important location for forecasting cyclones in the western Indian Ocean; wildlife sanctuary (seabirds, tortoises)

Gabon

the country has maintained its pristine rain forest and rich biodiversity

Gambia, The

almost an enclave of Senegal; smallest country on the African mainland

Gaza Strip

once a strategic strip of land along Mideast-North African trade routes

Georgia

note 1: strategically located east of the Black Sea, Georgia controls much of the Caucasus Mountains and the routes through them

note 2: the world's four deepest caves are all in Georgia, including two that are the only known caves on earth deeper than 2,000 m: Krubera Cave at -2,197 m (-7,208 ft; reached in 2012) and Veryovkina Cave at -2,212 (-7,257 ft; reached in 2018)

Germany

strategic location on North European Plain and along the entrance to the Baltic Sea; most major rivers in Germany -- the Rhine, Weser, Oder, Elbe -- flow northward; the Danube, which originates in the Black Forest, flows eastward

Ghana

Lake Volta is the world's largest artificial lake (manmade reservoir) by surface area (8,482 sq km; 3,275 sq mi); the lake was created after the Akosombo Dam was completed in 1965

Gibraltar

strategic location on Strait of Gibraltar that links the North Atlantic Ocean and Mediterranean Sea

Greece

strategic location dominating the Aegean Sea and southern approach to Turkish Straits; a peninsular country, with an archipelago of about 2,000 islands

Greenland

dominates North Atlantic Ocean between North America and Europe; sparse population confined to small settlements along coast; close to one-quarter of the population lives in the capital, Nuuk; world's second largest ice sheet after that of Antarctica, covering an area of 1.71 million sq km (660,000 sq mi), or about 79% of the island, and containing 2.85 million cu km (684 thousand cu mi) of ice (almost 7% of the world's fresh water)

Guam

largest and southernmost island in the Mariana Islands archipelago and the largest island in Micronesia; strategic location in western North Pacific Ocean

Guatemala

note 1: despite having both eastern and western coastlines (Caribbean Sea and Pacific Ocean), there are no natural harbors on the west coast

note 2: Guatemala is one of the countries along the Ring of Fire, which is a belt bordering the Pacific Ocean that contains about 75% of the world's volcanoes and up to 90% of the world's earthquakes

Guernsey

large, deepwater harbor at Saint Peter Port

Guinea

the Niger and its important tributary, the Milo River, have their sources in the Guinean highlands

Guinea-Bissau

this small country is swampy along its western coast and is low-lying inland

Guyana

the third-smallest country in South America after Suriname and Uruguay; contains some of the largest unspoiled rainforests on the continent

Haiti

shares island of Hispaniola with Dominican Republic (western one-third is Haiti, eastern two-thirds is the Dominican Republic); it is the most mountainous nation in the Caribbean

Heard Island and McDonald Islands

Mawson Peak on Heard Island is the highest Australian mountain; at 2,745 m (9,006 ft), Mawson is taller than Mt. Kosciuszko in mainland Australia), and one of only two active volcanoes located in Australian territory; in 1992, McDonald Island, the other active volcano, broke its dormancy and began erupting; it has erupted several times since

Holy See (Vatican City)

landlocked; an enclave in Rome, Italy; world's smallest state

Honduras

has only a short Pacific coast but a long Caribbean shoreline, including the virtually uninhabited eastern Mosquito Coast

Hong Kong

consists of a mainland area (the New Territories) and over 200 islands

Hungary

landlocked; strategic location on main land routes between Western Europe and Balkan Peninsula, as well as between Ukraine and the Mediterranean basin; the Duna (Danube) and Tisza Rivers divide the country into three large regions

Iceland

strategic location between Greenland and Europe; westernmost European country; Reykjavik is the northernmost national capital in the world; more land covered by glaciers than in all of continental Europe

India

dominates South Asian subcontinent; near important Indian Ocean trade routes; Kanchenjunga, third tallest mountain in the world, lies on the border with Nepal

Indian Ocean

major chokepoints include Bab el Mandeb, Strait of Hormuz, Strait of Malacca, southern access to the Suez Canal, and the Lombok Strait

Indonesia

note 1: 13,466 islands are in the archipelago, of which 922 are permanently inhabited; Indonesia is the world's largest country composed solely of islands; the country straddles the equator and occupies a strategic location along major sea lanes from the Indian Ocean to the Pacific Ocean

note 2: Indonesia is one of the countries along the Ring of Fire, which is a belt bordering the Pacific Ocean that contains about 75% of the world's volcanoes, up to 90% of the world's earthquakes, and 80% of tsunamis

note 3: despite having the fourth largest population in the world, Indonesia is the most heavily forested region on earth after the Amazon

Iran

strategic location on the Persian Gulf and Strait of Hormuz

Iraq

strategic location on Shatt al Arab waterway and at the head of the Persian Gulf

Ireland

strategic location on major air and sea routes between North America and northern Europe; over 40% of the population resides within 100 km of Dublin

Isle of Man

one small islet, the Calf of Man, lies to the southwest and is a bird sanctuary

Israel

note 1: Lake Tiberias (Sea of Galilee) is an important freshwater source; the Dead Sea is the second saltiest body of water in the world (after Lake Assal in Djibouti)

note 2: the Malham Cave in Mount Sodom is the world's longest salt cave at 10 km (6 mi); Mount Sodom is a hill about 220 m (722 ft) high that is 80% salt, with multiple salt layers covered by a veneer of rock

Italy

strategic location dominating central Mediterranean, as well as southern sea and air approaches to Western Europe

Jamaica

third largest island in the Caribbean (after Cuba and Hispaniola); strategic location between Cayman Trench and Jamaica Channel, the main sea lanes for the Panama Canal

Jan Mayen

barren volcanic spoon-shaped island with some moss and grass flora; island consists of two parts: a larger northeast Nord-Jan (the spoon "bowl") and the smaller Sor-Jan (the "handle"), linked by a 2.5 km-wide isthmus (the "stem") with two large lakes, Sorlaguna (South Lagoon) and Nordlaguna (North Lagoon)

Japan

note 1: strategic location in northeast Asia; composed of four main islands (the "Home Islands") -- Hokkaido, Honshu (the largest, most populous, and site of Tokyo, the capital), Shikoku, and Kyushu  

note 2: a 2023 Geospatial Information Authority of Japan survey detected 100,000 islands and islets, but only the 14,125 islands with a circumference of at least 100 m (330 ft) were officially counted; about 260 of the islands are inhabited

note 3: Japan annually records the most earthquakes in the world; it is one of the countries along the Ring of Fire, which is a belt bordering the Pacific Ocean that contains about 75% of the world's volcanoes and up to 90% of the world's earthquakes

Jersey

largest and southernmost of Channel Islands; about 30% of population concentrated in Saint Helier

Jordan

strategic location at the head of the Gulf of Aqaba; the Arab country that shares the longest border with Israel and the West Bank; the Dead Sea, the lowest point in Asia and the second saltiest body of water in the world (after Lac Assal in Djibouti), lies on Jordan's western border with Israel and the West Bank; Jordan is almost landlocked but does have a 26 km southwestern coastline with a single port, Al 'Aqabah (Aqaba)

Kazakhstan

world's largest landlocked country and one of only two landlocked countries in the world that extends into two continents (the other is Azerbaijan); Russia leases approximately 6,000 sq km (2,317 sq mi) of territory enclosing the Baikonur Cosmodrome 

Kenya

the Kenyan Highlands comprise one of the most successful agricultural production regions in Africa; glaciers are found on Mount Kenya, Africa's second-highest peak; unique physiography supports abundant and varied wildlife of scientific and economic value; Lake Victoria, the world's largest tropical lake and the second-largest freshwater lake, is shared among three countries: Kenya, Tanzania, and Uganda

Kiribati

21 of the 33 islands are inhabited; Banaba (Ocean Island) in Kiribati is one of the three great phosphate rock islands in the Pacific Ocean -- the others are Makatea in French Polynesia, and Nauru; Kiribati is the only country in the world to fall into all four hemispheres (northern, southern, eastern, and western)

Korea, North

strategic location bordering China, South Korea, and Russia; mountainous interior is isolated and sparsely populated

Korea, South

strategic location on Korea Strait; about 3,000 mostly small and uninhabited islands lie off the western and southern coasts

Kosovo

the 41-km (25-mi) Nerodimka River divides into two branches, each of which flows into a different sea: the northern branch flows into the Sitnica River, which via the Ibar, Morava, and Danube Rivers ultimately flows into the Black Sea; the southern branch flows via the Lepenac and Vardar Rivers into the Aegean Sea

Kuwait

strategic location at head of Persian Gulf

Kyrgyzstan

landlocked; entirely mountainous, dominated by the Tien Shan range; 94% of the country is 1,000 m above sea level with an average elevation of 2,750 m; many tall peaks, glaciers, and high-altitude lakes

Laos

landlocked; most of the country is mountainous and thickly forested; the Mekong River forms a large part of the western boundary with Thailand

Latvia

most of the country is composed of fertile low-lying plains with some hills in the east

Lebanon

smallest country in continental Asia; Nahr el Litani is the only major river in Near East not crossing an international boundary

Lesotho

landlocked, surrounded by South Africa; mountainous, more than 80% of the country is 1,800 m (5,900 ft) above sea level

Liberia

facing the Atlantic Ocean, the coastline is characterized by lagoons, mangrove swamps, and river-deposited sandbars; the inland grassy plateau supports limited agriculture

Libya

note 1: more than 90% of the country is desert or semidesert

note 2: the volcano Waw an Namus lies in south central Libya in the middle of the Sahara; the caldera is an oasis -- the name means "oasis of mosquitoes" -- containing several small lakes that host many species of insects and birds

Liechtenstein

along with Uzbekistan, one of only two doubly landlocked countries in the world; variety of microclimatic variations based on elevation

Lithuania

fertile central plains are separated by hilly uplands that are ancient glacial deposits

Luxembourg

landlocked

Macau

primarily urban; an area of land reclaimed from the sea measuring 5.2 sq km (2 sq mi) and known as Cotai now connects the islands of Coloane and Taipa; the island area is connected to the mainland peninsula by three bridges

Madagascar

world's fourth-largest island; strategic location along Mozambique Channel; despite Madagascar’s close proximity to the African continent, ocean currents isolate the island, resulting in high rates of endemic plant and animal species; approximately 90% of the flora and fauna on the island are found nowhere else

Malawi

landlocked; Lake Nyasa, about 580 km (360 mi) long, is the country's most prominent physical feature; it contains more fish species than any other lake on earth

Malaysia

strategic location along Strait of Malacca and southern South China Sea

Maldives

smallest Asian country; archipelago of 1,190 coral islands grouped into 26 atolls (200 inhabited islands, plus 80 islands with tourist resorts); strategic location along major sea lanes in Indian Ocean

Mali

landlocked; divided into three natural zones: the southern, cultivated Sudanese; the central, semiarid Sahelian; and the northern, arid Saharan

Malta

the country is an archipelago, with only the three largest islands (Malta, Ghawdex or Gozo, and Kemmuna or Comino) inhabited; numerous bays provide good harbors

Marshall Islands

Kwajalein atoll surrounds the world's largest lagoon; the island city of Ebeye is the second largest settlement in the Marshall Islands, after the capital of Majuro, and one of the most densely populated locations in the Pacific

Mauritania

Mauritania is considered part of both North Africa's Maghreb region and West Africa's Sahel region; most of the population is concentrated in the cities of Nouakchott and Nouadhibou and along the Senegal River in the southern part of the country

Mauritius

the main island, from which the country derives its name, is of volcanic origin and is almost entirely surrounded by coral reefs; former home of the extinct dodo, a large flightless bird related to pigeons

Mexico

note 1: strategic location on southern border of the US; Mexico is one of the countries along the Ring of Fire, which is a belt bordering the Pacific Ocean that contains about 75% of the world's volcanoes and up to 90% of the world's earthquakes

note 2: the Sac Actun cave system at 348 km (216 mi) is the longest underwater cave in the world and the second longest cave worldwide, after Mammoth Cave in the United States (see "Geography - note" under United States)

note 3: the prominent Yucatán Peninsula that divides the Gulf of America from the Caribbean Sea is shared by Mexico, Guatemala, and Belize; on the northern coast of Yucatan near the town of Chicxulub lie the remnants of a massive asteroid or comet crater about 150 km (93 mi) in diameter and extending into the Gulf of America; the impact is believed to have initiated a worldwide climate disruption that caused a mass extinction of 75% of the earth's plant and animal species, including the non-avian dinosaurs

Micronesia, Federated States of

composed of four major island groups totaling 607 islands

Moldova

landlocked; has many types of sedimentary rocks and minerals, including sand, gravel, gypsum, and limestone

Monaco

second-smallest independent state in the world (after the Holy See); smallest country with a coastline; almost entirely urban

Mongolia

landlocked; strategic location between China and Russia

Montenegro

strategic location along the Adriatic coast

Montserrat

the island is entirely volcanic in origin and composed of three major volcanic centers of differing ages

Morocco

strategic location along Strait of Gibraltar; the only African nation to have both Atlantic and Mediterranean coastlines; the waters off the Atlantic coast are particularly rich fishing areas

Mozambique

the Zambezi River flows through the north-central and most fertile part of the country

Namibia

the Namib Desert, after which the country is named, is considered to be the oldest desert in the world; some 14% of the land is protected, including virtually the entire Namib Desert coastal strip

Nauru

Nauru is the third-smallest country in the world behind the Holy See (Vatican City) and Monaco; it is the smallest country in the Pacific Ocean, the smallest country outside Europe, the world's smallest island country, and the world's smallest independent republic; situated just 53 km south of the equator, Nauru is one of the three great phosphate rock islands in the Pacific Ocean -- the others are Banaba (Ocean Island) in Kiribati and Makatea in French Polynesia

Navassa Island

strategic location 160 km south of the US Naval Base at Guantanamo Bay, Cuba; mostly exposed rock with numerous solution holes (limestone sinkholes) but with enough grassland to support goat herds; dense stands of fig trees, scattered cactus

Nepal

landlocked; strategic location between China and India; contains eight of world's 10 highest peaks, including Mount Everest and Kanchenjunga -- the world's tallest and third-tallest mountains -- on the borders with China and India, respectively

Netherlands

located at mouths of three major European rivers (Rhine (Rijn), Meuse (Maas), and Scheldt (Schelde)); about a quarter of the country lies below sea level and only about half of the land exceeds one meter above sea level

New Caledonia

consists of the main island of New Caledonia (one of the largest in the Pacific Ocean), the archipelago of Iles Loyauté, and numerous small, sparsely populated islands and atolls

New Zealand

note 1: consists of two main islands and a number of smaller islands; South Island, the larger main island, is the 12th-largest island in the world and is divided along its length by the Southern Alps; North Island is the 14th-largest island in the world and is not as mountainous, but it is marked by volcanism

note 2: New Zealand lies along the Ring of Fire, which is a belt bordering the Pacific Ocean that contains about 75% of the world's volcanoes and up to 90% of the world's earthquakes

note 3: almost 90% of the population lives in cities and over three-quarters on North Island; Wellington is the southernmost national capital in the world

Nicaragua

largest country in Central America; contains the largest freshwater body in Central America, Lago de Nicaragua

Niger

landlocked; one of the hottest countries in the world; northern four-fifths is desert, southern one-fifth is savanna that is suitable for livestock and limited agriculture

Nigeria

the Niger River enters the country in the northwest and flows southward through tropical rainforests and swamps to its delta in the Gulf of Guinea

Niue

one of world's largest coral islands; the only major break in the surrounding coral reef occurs in the central western part of the coast

Norfolk Island

most of the 32-km (20-mi) coastline consists of almost inaccessible cliffs, but the land slopes down to the sea in one small southern area on Sydney Bay, where the capital of Kingston is located

North Macedonia

landlocked; major transportation corridor from Western and Central Europe to Aegean Sea and Southern Europe to Western Europe

Northern Mariana Islands

strategic location in the North Pacific Ocean

Norway

about two-thirds mountains; some 50,000 islands off its much-indented coastline; strategic location adjacent to sea lanes and air routes in North Atlantic; one of the most rugged and longest coastlines in the world

Oman

consists of Oman proper and two northern exclaves, Musandam and Al Madhah; the former is a peninsula that occupies a strategic location adjacent to the Strait of Hormuz

Pacific Ocean

the major chokepoints are the Bering Strait, Panama Canal, Luzon Strait, and the Singapore Strait; the equator divides the Pacific Ocean into the North Pacific Ocean and the South Pacific Ocean; dotted with low coral islands and rugged volcanic islands in the southwestern Pacific Ocean; much of the Pacific Ocean's rim lies along the Ring of Fire, which is a belt that contains about 75% of the world's volcanoes and up to 90% of the world's earthquakes; the Pacific Ocean is the deepest ocean basin, averaging 4,000 m (13,123 ft) in depth

Pakistan

controls Khyber Pass and Bolan Pass, traditional invasion routes between Central Asia and India

Palau

westernmost archipelago in the Caroline chain, consists of six island groups totaling more than 300 islands; includes world-famous Rock Islands

Panama

strategic location on eastern end of isthmus forming land bridge that connects North and South America; controls the Panama Canal, which links the North Atlantic Ocean with the North Pacific Ocean via the Caribbean Sea 

Papua New Guinea

note 1: shares island of New Guinea with Indonesia; highlands that trend from east to west break up New Guinea into diverse ecoregions; one of world's largest swamps lies along the southwest coast

note 2: Papua New Guinea is one of the countries along the Ring of Fire, which is a belt bordering the Pacific Ocean that contains about 75% of the world's volcanoes and up to 90% of the world's earthquakes

Paracel Islands

composed of 130 small coral islands and reefs divided into the northeast Amphitrite Group and the western Crescent Group

Paraguay

landlocked; lies between Argentina, Bolivia, and Brazil; population concentrated in eastern and southern part of country

Peru

note 1: shares control of Lago Titicaca, world's highest navigable lake, with Bolivia; a remote slope of Nevado Mismi, a 5,316-m (17,441-ft) peak, is the ultimate source of the Amazon River

note 2: Peru is one of the countries along the Ring of Fire, which is a belt bordering the Pacific Ocean that contains about 75% of the world's volcanoes and up to 90% of the world's earthquakes

note 3: on 19 February 1600, Mount Huaynaputina in the southern Peruvian Andes erupted in the largest volcanic explosion in South America in historical times; intermittent eruptions lasted until 5 March 1600 and pumped an estimated 16 to 32 million metric tons of particulates into the atmosphere, reducing the amount of sunlight reaching the earth's surface and affecting weather worldwide; over the next two-and-a-half years, millions died around the globe in famines from bitterly cold winters, cool summers, and the loss of crops and animals

Philippines

note 1: for decades, the Philippine archipelago was reported as having 7,107 islands; in 2016, the national mapping authority reported that hundreds of new islands had been discovered and increased the number of islands to 7,641, though not all of the new islands have been verified

note 2: the Philippines is one of the countries along the Ring of Fire, which is a belt bordering the Pacific Ocean that contains about 75% of the world's volcanoes and up to 90% of the world's earthquakes

note 3: the Philippines sits on the Pacific typhoon belt, and an average of 9 typhoons make landfall on the islands each year, with about 5 being destructive; the country is the most exposed in the world to tropical storms

Pitcairn Islands

Britain's most isolated dependency; only the larger island of Pitcairn is inhabited, but it has no port or natural harbor; supplies must be transported by longboat from larger ships stationed offshore

Poland

historically an area of conflict because of flat terrain and the lack of natural barriers on the North European Plain

Portugal

Azores and Madeira Islands occupy strategic locations along western sea approaches to Strait of Gibraltar; they are two of the four North Atlantic archipelagos that make up Macaronesia; the others are the Canary Islands (Spain) and Cabo Verde

Puerto Rico

important location along the Mona Passage, a key shipping lane to the Panama Canal; San Juan is one of the biggest and best natural harbors in the Caribbean; many small rivers and high central mountains ensure land is well-watered; south coast relatively dry; fertile coastal plain belt in north

Qatar

the peninsula occupies a strategic location in the central Persian Gulf near major petroleum deposits

Romania

controls the most easily traversable land route between the Balkans, Moldova, and Ukraine; the Carpathian Mountains dominate the center of the country, and the Danube River forms much of the southern boundary with Serbia and Bulgaria

Russia

note 1: largest country in the world in terms of area; despite its size, much of the country lacks the soil and climate (either too cold or too dry) for agriculture

note 2: Russia's far east, particularly the Kamchatka Peninsula, lies along the Ring of Fire, which is a belt bordering the Pacific Ocean that contains about 75% of the world's volcanoes and up to 90% of the world's earthquakes

note 3: Mount El'brus is Europe's tallest peak; Lake Baikal, the deepest lake in the world, is estimated to hold one fifth of the world's fresh surface water

note 4: Kaliningrad oblast is an exclave annexed from Germany after World War II; its capital city of Kaliningrad -- formerly Koenigsberg -- is the only Baltic port in Russia that remains ice-free in the winter

Rwanda

landlocked; most of the country is intensively cultivated and rugged, with the population predominantly rural

Saint Barthelemy

a 1,200-hectare (3,000-acre) marine nature reserve, the Reserve Naturelle, is made up of five zones around the island that form a network to protect the island's coral reefs, seagrass, and endangered marine species

Saint Helena, Ascension, and Tristan da Cunha

Saint Helena harbors at least 40 species of plants unknown elsewhere in the world; Ascension is a breeding ground for sea turtles and sooty terns; Queen Mary's Peak on Tristan da Cunha is the highest island mountain in the South Atlantic and a prominent landmark on the sea lanes around southern Africa

Saint Kitts and Nevis

smallest country in the Western Hemisphere in terms of both area and population; the two volcanic islands are separated by a 3-km-wide (9-mi-wide) channel called The Narrows; on the southern tip of baseball-bat-shaped Saint Kitts lies the Great Salt Pond; Nevis Peak sits in the center of its ball-shaped namesake island

Saint Lucia

the twin Pitons (Gros Piton and Petit Piton), striking cone-shaped peaks south of Soufrière, are one of the scenic natural highlights of the Caribbean

Saint Martin

note 1: the southern border is shared with Sint Maarten, which is part of the Kingdom of the Netherlands; together, these two entities make up the smallest landmass in the world that is shared by two self-governing states

note 2: Simpson Bay Lagoon (aka Simson Bay Lagoon or The Great Pond) is one of the largest inland lagoons in the West Indies; the border between the French and Dutch halves of the island runs across the center of the lagoon, which is shared by both of the island's entities

Saint Pierre and Miquelon

vegetation scanty; the islands are part of the northern Appalachians, along with Newfoundland

Saint Vincent and the Grenadines

the administration of the islands of the Grenadines group is divided between Saint Vincent and the Grenadines and Grenada; Saint Vincent and the Grenadines is composed of 32 islands and cays

Samoa

occupies an almost central position within Polynesia

San Marino

landlocked; an enclave of (completely surrounded by) Italy; smallest independent state in Europe after the Holy See and Monaco; dominated by the Apennine Mountains

Sao Tome and Principe

the second-smallest African country (after the Seychelles); the two main islands form part of a chain of extinct volcanoes, and both are mountainous

Saudi Arabia

Saudi Arabia is the largest country in the world without a river; extensive coastlines on the Persian Gulf and Red Sea allow for considerable shipping (especially of crude oil) through the Persian Gulf and Suez Canal

Senegal

westernmost country on the African continent; The Gambia is almost an enclave within Senegal

Serbia

landlocked; controls one of the major land routes from Western Europe to Turkey and the Near East

Seychelles

the smallest African country in terms of both area and population; the constitution of the Republic of Seychelles lists 155 islands, including 42 granitic and 113 coralline; the largest island by far is Mahe, which is home to about 90% of the population and is the site of the capital city of Victoria

Sierra Leone

rainfall along the coast can reach 495 cm (195 in) a year, making it one of the wettest places along coastal western Africa

Singapore

focal point for Southeast Asian sea routes; consists of about 60 islands, the largest of which by far is Pulau Ujong; land reclamation has removed many former islands and created a number of new ones

Sint Maarten

note 1: the northern border is shared with the French overseas collectivity of Saint Martin; together, these two entities make up the smallest landmass in the world that is shared by two self-governing states

note 2: Simpson Bay Lagoon (aka, Simson Bay Lagoon or The Great Pond) is one of the largest inland lagoons in the West Indies; the border between the French and Dutch halves of the island of Saint Martin runs across the center of the lagoon, which is shared

Slovakia

landlocked; most of the country is rugged and mountainous; the Tatra Mountains in the north are interspersed with many scenic lakes and valleys

Slovenia

despite its small size, this eastern Alpine country controls some of Europe's major transit routes

Solomon Islands

strategic location on sea routes between the South Pacific Ocean, the Solomon Sea, and the Coral Sea; Rennell Island, the southernmost in the Solomon Islands chain, is one of the world’s largest raised coral atolls; the island’s Lake Tegano, formerly a lagoon on the atoll, is the largest lake in the insular Pacific (15,500 hectares; 38,300 acres)

Somalia

strategic location on Horn of Africa along southern approaches to Bab el Mandeb and route through Red Sea and Suez Canal

South Africa

note 1: South Africa completely surrounds Lesotho and almost completely surrounds Eswatini

note 2: sometimes mistaken for the southernmost point of Africa, the Cape of Good Hope is more accurately described as the southwestern-most point of the African continent; Cape Agulhas, the meeting point of the Atlantic and Indian Oceans, is the southernmost point of the African continent

South Georgia and South Sandwich Islands

the north coast of South Georgia has several large bays, which provide good anchorage

South Sudan

landlocked; The Sudd is a vast swamp in the north central region of South Sudan, formed by the White Nile; its size is variable but can reach some 15% of the country's total area during the rainy season; it is one of the world's largest wetlands

Southern Ocean

the major chokepoint is the Drake Passage between South America and Antarctica; the Polar Front (Antarctic Convergence) is the best natural definition of the northern extent of the Southern Ocean; it is a distinct region at the middle of the Antarctic Circumpolar Current that separates the cold polar surface waters to the south from the warmer waters to the north; the Front and the Current extend entirely around Antarctica, reaching south of 60 degrees south near New Zealand and near 48 degrees south in the far South Atlantic, coinciding with the path of the maximum westerly winds

Spain

strategic location along approaches to Strait of Gibraltar; Spain controls a number of territories in northern Morocco, including the enclaves of Ceuta and Melilla and the islands of Penon de Velez de la Gomera, Penon de Alhucemas, and Islas Chafarinas; Spain's Canary Islands are one of four North Atlantic archipelagos that make up Macaronesia; the others are the Azores (Portugal), Madeira (Portugal), and Cabo Verde

Spratly Islands

strategically located near several primary shipping lanes in the central South China Sea; includes numerous small islands, atolls, shoals, and coral reefs

Sri Lanka

strategic location near major Indian Ocean sea lanes; Adam's Bridge is a chain of limestone shoals between the southeastern coast of India and the northwestern coast of Sri Lanka; geological evidence suggests that this 50-km (31-mi) bridge once connected India and Sri Lanka; ancient records seem to indicate that a foot passage was possible between the two land masses until the 15th century, when the land bridge broke up in a cyclone

Sudan

the Nile is Sudan's primary water source; its major tributaries, the White Nile and the Blue Nile, meet at Khartoum to form the River Nile, which flows northward through Egypt to the Mediterranean Sea

Suriname

smallest independent country on the South American continent; mostly tropical rainforest; great diversity of flora and fauna; relatively small population, mostly along the coast

Svalbard

northernmost part of the Kingdom of Norway; consists of nine main islands; glaciers and snowfields cover 60% of the total area

Sweden

strategic location along Danish Straits linking Baltic and North Seas; Sweden has almost 100,000 lakes, the largest of which, Vanern, is the third-largest in Europe

Switzerland

landlocked; crossroads of northern and southern Europe; along with southeastern France, northern Italy, and southwestern Austria, has the highest elevations in the Alps

Syria

the capital of Damascus is located at an oasis fed by the Barada River and is thought to be one of the world's oldest continuously inhabited cities; there are Israeli settlements and civilian land-use sites in the Israeli-controlled Golan Heights (2017)

Taiwan

strategic location adjacent to both the Taiwan Strait and the Luzon Strait

Tajikistan

landlocked; highest point, Qullai Ismoili Somoni (formerly Communism Peak), was the tallest mountain in the former USSR

Tanzania

Kilimanjaro is the highest point in Africa and one of only three mountain ranges on the continent that has glaciers (the others are Mount Kenya in Kenya and the Ruwenzori Mountains on the Uganda-Democratic Republic of the Congo border); Tanzania is bordered by three of the largest lakes on the continent: Lake Victoria (the world's second-largest freshwater lake) in the north, Lake Tanganyika (the world's second-deepest) in the west, and Lake Nyasa (Lake Malawi) in the southwest

Thailand

controls only land route from Asia to Malaysia and Singapore

Timor-Leste

the island of Timor is part of the Malay Archipelago and is the largest and easternmost of the Lesser Sunda Islands; the district of Oecussi is an exclave separated from Timor-Leste proper by Indonesia; Timor-Leste is the only Asian country located completely in the Southern Hemisphere

Togo

stretches through six distinct geographic regions; climate varies from tropical to savanna

Tokelau

consists of three atolls (Atafu, Fakaofo, Nukunonu), each with a lagoon surrounded by a number of reef-bound islets of varying length and rising to over 3 m (10 ft) above sea level

Tonga

the western islands (making up the Tongan Volcanic Arch) are all of volcanic origin; the eastern islands are nonvolcanic and are composed of coral limestone and sand

Trinidad and Tobago

Pitch Lake, on Trinidad's southwestern coast, is the world's largest natural reservoir of asphalt

Tunisia

strategic location in central Mediterranean

Turkey (Turkiye)

strategic location controlling the Turkish Straits (Bosporus, Sea of Marmara, Dardanelles) that link the Black and Aegean Seas; the 3% of Turkish territory north of the Straits lies in Europe and goes by the names of European Turkey, Eastern Thrace, or Turkish Thrace; the 97% of the country in Asia is referred to as Anatolia; Istanbul, which straddles the Bosporus, is the only metropolis in the world located on two continents; Mount Ararat, reputed to be the landing place of Noah's ark, is in the far-eastern part of the country

Turkmenistan

landlocked; the western and central low-lying desolate portions of the country make up the great Garagum (Kara-Kum) desert, which occupies over 80% of the country; eastern part is plateau

Turks and Caicos Islands

include eight large islands and numerous smaller cays, islets, and reefs; only two of the Caicos Islands and six of the Turks group are inhabited

Tuvalu

one of the smallest and most remote countries on earth; six of the nine coral atolls -- Nanumea, Nui, Vaitupu, Nukufetau, Funafuti, and Nukulaelae -- have lagoons open to the ocean; Nanumaya and Niutao have landlocked lagoons; Niulakita does not have a lagoon

Uganda

landlocked; fertile, well-watered country with many lakes and rivers; Lake Victoria, the world's largest tropical lake and second-largest freshwater lake, is shared among three countries: Kenya, Tanzania, and Uganda

Ukraine

strategic position at the crossroads between Europe and Asia; second-largest country in Europe after Russia

United Arab Emirates

strategic location along southern approaches to Strait of Hormuz, a transit point for crude oil; Abu Zaby (Abu Dhabi) and Dubayy (Dubai) together account for over 90% of UAE's area and two-thirds of the population

United Kingdom

lies near vital North Atlantic sea lanes; only 35 km (22 mi) from France and linked by tunnel under the English Channel (the Channel Tunnel or Chunnel); because of heavily indented coastline, no location is more than 125 km (78 mi) from tidal waters

United States

note 1: world's third-largest country by size (after Russia and Canada) and by population (after China and India); Mt. McKinley is the highest point (6,190 m; 20,308 ft) in North America, and Death Valley is the lowest point (-86 m; -282 ft)

note 2: the western US coast and the southern coast of Alaska lie along the Ring of Fire, which is a belt bordering the Pacific Ocean that contains about 75% of the world's volcanoes and up to 90% of the world's earthquakes

note 3: the Aleutian Islands are a chain of volcanic islands that divide the Bering Sea (north) from the main Pacific Ocean (south); they extend about 1,800 km (1,118 mi) westward from the Alaskan Peninsula; the archipelago consists of 14 larger islands, 55 smaller islands, and hundreds of islets; there are 41 active volcanoes on the islands, which together form a large northern section of the Ring of Fire

note 4: Mammoth Cave, in west-central Kentucky, is the world's longest known cave system with more than 650 km (405 miles) of surveyed passageways, which is nearly twice as long as the second-longest cave system, the Sac Actun underwater cave in Mexico (see "Geography - note" under Mexico)

note 5: Kazumura Cave on the island of Hawaii is the world's longest and deepest lava-tube cave; it has been surveyed at 66 km (41 mi) long and 1,102 m (3,614 ft) deep

note 6: Bracken Cave outside San Antonio, Texas is the world's largest bat cave and the summer home to the largest colony of bats in the world; an estimated 20 million Mexican free-tailed bats roost in the cave from March to October, making it the world's largest known concentration of mammals

United States Pacific Island Wildlife Refuges

Baker, Howland, and Jarvis Islands: scattered vegetation consisting of grasses, vines, and low-growing shrubs; primarily a nesting, roosting, and foraging habitat for seabirds, shorebirds, and marine wildlife; closed to the public

Johnston Atoll: Johnston Island and Sand Island are natural islands that have been expanded by coral dredging; North Island (Akau) and East Island (Hikina) are manmade islands formed from coral dredging; the egg-shaped reef is 34 km (21 mi) in circumference; closed to the public

Kingman Reef: barren coral atoll with deep interior lagoon; closed to the public

Midway Islands: a coral atoll managed as a National Wildlife Refuge and open to the public for wildlife observation and photography

Palmyra Atoll: high rainfall and lush vegetation make the environment of this atoll unique among the US Pacific Island territories; supports a large undisturbed stand of Pisonia beach forest

Uruguay

second-smallest South American country (after Suriname); most of the low-lying landscape (three-quarters of the country) is grassland, ideal for cattle and sheep

Uzbekistan

along with Liechtenstein, one of the only two doubly landlocked countries in the world

Vanuatu

a Y-shaped chain of four main islands and 80 smaller islands; several of the islands have active volcanoes, including several underwater volcanoes

Venezuela

note 1: the country lies on major sea and air routes linking North and South America

note 2: Venezuela has some of the most unique geology in the world; tepuis are the massive table-top mountains of the western Guiana Highlands that tend to be isolated and thus support unique endemic plant and animal species; their sheer cliffsides help create some of the most spectacular waterfalls in the world, including Angel Falls, the world's highest (979 m; 3,212 ft) that drops from Auyan Tepui

Vietnam

note 1: extending 1,650 km (1,025 mi) north to south, the country is only 50 km (31 mi) across at its narrowest point

note 2: Son Doong in Phong Nha-Ke Bang National Park is the world's largest cave (greatest cross-sectional area) and is the largest known cave passage in the world by volume at 38.5 million cu m (about 1.35 billion cu ft); it connects to Thoong cave, but not yet officially -- when recognized, it will add an additional 1.6 million cu m; it is so massive that it contains its own jungle, underground river, and localized weather system, with clouds forming inside the cave and spewing from its exits

Virgin Islands

important location along the Anegada Passage, a key shipping lane for the Panama Canal; Saint Thomas has one of the best natural deepwater harbors in the Caribbean

Wake Island

strategic location in the North Pacific Ocean

Wallis and Futuna

both island groups have fringing reefs; Wallis contains several prominent crater lakes

West Bank

landlocked; highlands are main recharge area for Israel's coastal aquifers (2017)

World

note: the Earth is now thought to be about 4.55 billion years old, about one-third of the 13.8-billion-year age estimated for the universe; the earliest widely accepted date for life appearing on Earth is 3.48 billion years ago

Yemen

strategic location on Bab el Mandeb, the strait linking the Red Sea and the Gulf of Aden and one of world's most active shipping lanes

Zambia

landlocked; the Zambezi forms a natural river boundary with Zimbabwe; Lake Kariba on the Zambia-Zimbabwe border forms the world's largest reservoir by volume (180 cu km; 43 cu mi)

Zimbabwe

landlocked; the Zambezi forms a natural river boundary with Zambia; in full flood (February-April), the massive Victoria Falls on the river forms the world's largest curtain of falling water; Lake Kariba on the Zambia-Zimbabwe border forms the world's largest reservoir by volume (180 cu km; 43 cu mi)