Terrain In 36 editions of 36.

• tremendous variation of terrain may be found on each of the continents, and a compilation of terrain extremes can be found in the World "Elevation" entry;
• the world's ocean floors also display extraordinary variation -- check the "Bathymetry" and "Major surface currents" entries under each of the five ocean entries (Arctic, Atlantic, Indian, Pacific, and Southern) for further information on oceanic environs

Top ten world caves:

compiled from "Geography - note(s)" under various country entries where more details may be found

largest cave:

• Son Doong in Phong Nha-Ke Bang National Park, Vietnam, is the world's largest cave (greatest cross sectional area) and is the largest known cave passage by volume;
• it currently measures a total of 38.5 million cu m (about 1.35 billion cu ft);
• it connects to Thung cave, but not yet officially -- when recognized, it will add an additional 1.6 million cu m in volume

largest ice cave:

the Eisriesenwelt (Ice Giants World) inside the Hochkogel mountain near Werfen, Austria, is the world's largest and longest ice cave system at 42 km (26 mi)

longest cave:

Mammoth Cave in west-central Kentucky is the world's longest known cave system with more than 650 km (405 mi) of surveyed passageways

longest salt cave:

• the Malham Cave in Mount Sodom in Israel is the world's longest salt cave at 10 km (6 mi);
• its survey is not complete, so its recorded length will eventually increase

longest underwater cave:

the Sac Actun cave system in Mexico is the longest underwater cave in the world at 348 km (216 mi), and the second longest cave worldwide

longest lava tube cave:

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

deepest cave:

Veryovkina Cave in the country of Georgia is the world's deepest cave, plunging down 2,212 m (7,257 ft)

deepest underwater cave:

the Hranice Abyss in Czechia is the world's deepest surveyed underwater cave at 404 m (1,325 ft); its survey is not complete, and it could be 800-1,200 m deep

largest cave chamber:

the Miao Room in the Gebihe cave system in China's Ziyun Getu He Chuandong National Park has about 10.78 million cu m (380.7 million cu ft) of volume

largest bat cave:

• Bracken Cave outside San Antonio, Texas, is the world's largest bat cave;
• 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

bonus "cave" - the world's largest sinkhole: the Xiaoxhai Tiankeng sinkhole in Chongqing Municipality, China is 660 m deep, with a volume of 130 million cu m

• mostly high plateau and desert;
• Atlas Mountains in the far north and Hoggar Mountains in the south;
• narrow, discontinuous coastal plain

narrow coastal plain rises abruptly to vast interior plateau

mostly flat to undulating plain; some hills and low mountains

predominantly flat to gently rolling tableland; Kalahari Desert in southwest

• mostly flat to dissected, undulating plains;
• hills in the west and southeast;
• o ccupies an extensive plateau with s avanna that is grassy in the north and gradually gives way to sparse forests in the south

• hilly and mountainous,
• dropping to a plateau in east,
• some plains

• steep,
• rugged,
• rocky,
• volcanic

• diverse,
• with coastal plain in southwest,
• dissected plateau in center,
• mountains in west,
• plains in north

vast, flat to rolling plateau; scattered hills in northeast and southwest

• broad,
• arid plains in center,
• desert in north,
• mountains in northwest,
• lowlands in south

volcanic islands, interiors vary from steep mountains to low hills

vast central basin is a low-lying plateau; mountains in east

• coastal plain,
• southern basin,
• central plateau,
• northern basin

mostly flat to undulating plains; mountains in northwest

coastal plain and plateau separated by central mountains

vast desert plateau interrupted by Nile valley and delta

coastal plains rise to interior hills; islands are volcanic

dominated by extension of Ethiopian north-south trending highlands, descending on the east to a coastal desert plain, on the northwest to hilly terrain and on the southwest to flat-to-rolling plains

mostly mountains and hills; some moderately sloping plains

high plateau with central mountain range divided by Great Rift Valley

• narrow coastal plain;
• hilly interior;
• savanna in east and south

flood plain of the Gambia River flanked by some low hills

mostly low plains with dissected plateau in south-central area

generally flat coastal plain, hilly to mountainous interior

• mostly low-lying coastal plain with a deeply indented estuarine coastline rising to savanna in east;
• numerous off-shore islands including the Arquipelago Dos Bijagos consisting of 18 main islands and many small islets

low plains rise to central highlands bisected by Great Rift Valley; fertile plateau in west

mostly highland with plateaus, hills, and mountains

mostly flat to rolling coastal plains rising to rolling plateau and low mountains in northeast

• mostly barren,
• flat to undulating plains,
• plateaus,
• depressions

narrow coastal plain, high plateau and mountains in center

• narrow elongated plateau with rolling plains,
• rounded hills,
• some mountains

mostly flat to rolling northern plains covered by sand; savanna in south, rugged hills in northeast

mostly barren, flat plains of the Sahara; some central hills

small coastal plain rising to discontinuous mountains encircling central plateau

• mountainous northern coast (Rif Mountains) and interior (Atlas Mountains) bordered by large plateaus with intermontane valleys, and fertile coastal plains;
• the south is mostly low, flat desert with large areas of rocky or sandy surfaces

• mostly coastal lowlands,
• uplands in center,
• high plateaus in northwest,
• mountains in west

• mostly high plateau;
• Namib Desert along coast;
• Kalahari Desert in east

• predominately desert plains and sand dunes;
• flat to rolling plains in south;
• hills in north

southern lowlands merge into central hills and plateaus; mountains in southeast, plains in north

mostly grassy uplands and hills; relief is mountainous with altitude declining from west to east

the islands of this group are of volcanic origin associated with the Atlantic Mid-Ocean Ridge

Saint Helena:

rugged, volcanic; small scattered plateaus and plains;

Ascension:

surface covered by lava flows and cinder cones of 44 dormant volcanoes; terrain rises to the east;

Tristan da Cunha:

• sheer cliffs line the coastline of the nearly circular island;
• the flanks of the central volcanic peak are deeply dissected;
• narrow coastal plain lies between The Peak and the coastal cliffs

volcanic, mountainous

• generally low,
• rolling,
• plains rising to foothills in southeast

• Mahe Group is volcanic with a narrow coastal strip and rocky, hilly interior;
• others are relatively flat coral atolls, or elevated reefs;
• sits atop the submarine Mascarene Plateau

• coastal belt of mangrove swamps,
• wooded hill country,
• upland plateau,
• mountains in east

mostly flat to undulating plateau rising to hills in north

vast interior plateau rimmed by rugged hills and narrow coastal plain

• plains in the north and center rise to southern highlands along the border with Uganda and Kenya;
• the White Nile, flowing north out of the uplands of Central Africa, is the major geographic feature of the country;
• The Sudd (a name derived from floating vegetation that hinders navigation) is a large swampy area of more than 100,000 sq km fed by the waters of the White Nile that dominates the center of the country

generally flat, featureless plain; desert dominates the north

• plains along coast;
• central plateau;
• highlands in north, south

• gently rolling savanna in north;
• central hills;
• southern plateau;
• low coastal plain with extensive lagoons and marshes

• mountains in north;
• hot, dry central plain;
• semiarid south merges into the Sahara

mostly plateau with rim of mountains

mostly high plateau with some hills and mountains

mostly high plateau with higher central plateau (high veld); mountains in east

• about 99% thick continental ice sheet and 1% barren rock, with average elevations between 2,000 and 4,000 m;
• mountain ranges up to nearly 5,000 m;
• ice-free coastal areas include parts of southern Victoria Land, Wilkes Land, the Antarctic Peninsula area, and parts of Ross Island on McMurdo Sound;
• glaciers form ice shelves along about half of the coastline, and floating ice shelves constitute 11% of the area of the continent

volcanic; coast is mostly inaccessible

Ile Amsterdam (Ile Amsterdam et Ile Saint-Paul):

a volcanic island with steep coastal cliffs; the center floor of the volcano is a large plateau;

Ile Saint-Paul (Ile Amsterdam et Ile Saint-Paul):

• triangular in shape,
• the island is the top of a volcano,
• rocky with steep cliffs on the eastern side;
• has active thermal springs;

Iles Crozet:

a large archipelago formed from the Crozet Plateau is divided into two groups of islands;

Iles Kerguelen:

the interior of the large island of Ile Kerguelen is composed of high mountains, hills, valleys, and plains with peninsulas stretching off its coasts;

Bassas da India (Iles Eparses):

atoll, awash at high tide; shallow (15 m) lagoon;

Europa Island, Glorioso Islands, Juan de Nova Island: low, flat, and sandy;

Tromelin Island (Iles Eparses):

• low,
• flat,
• sandy;
• likely volcanic seamount

Heard Island - 80% ice-covered, bleak and mountainous, dominated by a large massif (Big Ben) and an active volcano (Mawson Peak); McDonald Islands - small and rocky

• most of the islands are rugged and mountainous rising steeply from the sea;
• South Georgia is largely barren with steep, glacier-covered mountains;
• the South Sandwich Islands are of volcanic origin with some active volcanoes

• flat to gradually sloping icecap covers all but a narrow,
• mountainous,
• barren,
• rocky coast

mostly plateau interspersed with mountain peaks, icefields; coast deeply indented by bays and fiords

volcanic island, partly covered by glaciers

• rugged mountains;
• much of the upland areas are ice covered;
• west coast clear of ice about half the year;
• fjords along west and north coasts

mostly rugged mountains; plains in north and southwest

• Armenian Highland with mountains;
• little forest land;
• fast flowing rivers;
• good soil in Aras River valley

• large, flat Kur-Araz Ovaligi (Kura-Araks Lowland, much of it below sea level) with Great Caucasus Mountains to the north, Qarabag Yaylasi (Karabakh Upland) to the west;
• Baku lies on Abseron Yasaqligi (Apsheron Peninsula) that juts into Caspian Sea

mostly flat alluvial plain; hilly in southeast

mostly mountainous with some fertile valleys and savanna

flat and low coral atolls (most areas do not exceed two m in elevation); sits atop the submarine volcanic Chagos-Laccadive Ridge

mostly mountains, high plateaus, deserts in west; plains, deltas, and hills in east

• largely mountainous with Great Caucasus Mountains in the north and Lesser Caucasus Mountains in the south;
• Kolkhet'is Dablobi (Kolkhida Lowland) opens to the Black Sea in the west;
• Mtkvari River Basin in the east;
• fertile soils in river valley flood plains and foothills of Kolkhida Lowland

• upland plain (Deccan Plateau) in south,
• flat to rolling plain along the Ganges,
• deserts in west,
• Himalayas in north

mostly rugged and mountainous

vast flat steppe extending from the Volga in the west to the Altai Mountains in the east and from the plains of western Siberia in the north to oases and deserts of Central Asia in the south

• mostly hills and mountains separated by deep,
• narrow valleys;
• wide coastal plains in west,
• discontinuous in east

mostly hills and mountains; wide coastal plains in west and south

peaks of the Tien Shan mountain range and associated valleys and basins encompass the entire country

flat coral atolls, with white sandy beaches; sits atop the submarine volcanic Chagos-Laccadive Ridge

• vast semidesert and desert plains,
• grassy steppe,
• mountains in west and southwest;
• Gobi Desert in south-central

Tarai or flat river plain of the Ganges in south; central hill region with rugged Himalayas in north

divided into three major geographic areas:

the northern highlands, the Indus River plain in the center and east, and the Balochistan Plateau in the south and west

• broad plain with low hills west of Urals;
• vast coniferous forest and tundra in Siberia;
• uplands and mountains along southern border regions

mostly low, flat to rolling plain; mountains in south-central interior

• mountainous region dominated by the Alay Mountains in the north and the Pamirs in the southeast;
• western Fergana Valley in north, Kofirnihon and Vakhsh Valleys in southwest

• flat-to-rolling sandy desert with dunes rising to mountains in the south;
• low mountains along border with Iran;
• borders Caspian Sea in west

• mostly flat-to-rolling sandy desert with dunes;
• broad, flat intensely irrigated river valleys along course of Amu Darya, Syr Darya (Sirdaryo), and Zaravshan;
• Fergana Valley in east surrounded by mountainous Tajikistan and Kyrgyzstan;
• shrinking Aral Sea in west

flat and low-lying island of coral and limestone

mostly low-lying limestone and coral islands, with some higher volcanic areas

flat with a few hills; scant vegetation

long, flat coral formations with some low rounded hills

relatively flat; rises gently to central highland region

flat, swampy coastal plain; low mountains in south

coral islands relatively flat; volcanic islands steep, hilly

low-lying limestone base surrounded by coral reefs

coastal plains separated by rugged mountains including over 100 volcanic cones, of which several are major active volcanoes

mostly flat to rolling plains, with rugged hills and mountains in the southeast

generally low, hilly terrain

rugged mountains of volcanic origin

rugged highlands and mountains interspersed with fertile valleys

mostly mountains with narrow coastal belt and central plateau

volcanic in origin with central mountains

two east-west trending mountain chains divide the country into three regions: the mountainous highlands, the Pacific coast south of mountains, and the vast northern Peten lowlands

mostly rough and mountainous

mostly mountains in interior, narrow coastal plains

• mostly mountains,
• with narrow,
• discontinuous coastal plain

• volcanic island,
• mostly mountainous,
• with small coastal lowland

raised flat to undulating coral and limestone plateau; ringed by vertical white cliffs (9 to 15 m high)

extensive Atlantic coastal plains rising to central interior mountains; narrow Pacific coastal plain interrupted by volcanoes

• interior mostly steep,
• rugged mountains with dissected,
• upland plains;
• coastal plains with rolling hills

• mostly mountains with coastal plain in north;
• precipitous mountains to the sea on west coast;
• sandy beaches along most coastal areas

• hilly,
• almost completely surrounded by shallow-water reefs,
• with plentiful beaches

volcanic with mountainous interiors

volcanic and mountainous with broad, fertile valleys

volcanic, mountainous

• low,
• hilly terrain,
• volcanic origin

mostly plains with some hills and low mountains

low, flat limestone; extensive marshes and mangrove swamps

mostly hilly to rugged and mountainous with little flat land

mostly mountains and hills; small plains along coast

rugged mountains dissected by narrow valleys

mostly mountains (Alps) in the west and south; mostly flat or gently sloping along the eastern and northern margins

generally flat with much marshland

• flat coastal plains in northwest,
• central rolling hills,
• rugged mountains of Ardennes Forest in southeast

mountains and valleys

mostly mountains with lowlands in north and southeast

geographically diverse; flat plains along Hungarian border, low mountains and highlands near Adriatic coastline and islands

Bohemia in the west consists of rolling plains, hills, and plateaus surrounded by low mountains; Moravia in the east consists of very hilly country

low and flat to gently rolling plains

• marshy,
• lowlands;
• flat in the north,
• hilly in the south

fairly flat along Baltic and Atlantic coasts; mountainous in the central and southern areas

• rugged,
• rocky,
• some low peaks;
• cliffs along most of coast

mostly low, flat to rolling plains interspersed with lakes and low hills

metropolitan France:

mostly flat plains or gently rolling hills in north and west; remainder is mountainous, especially Pyrenees in south, Alps in east;

French Guiana:

low-lying coastal plains rising to hills and small mountains;

Guadeloupe:

• Basse-Terre is volcanic in origin with interior mountains;
• Grande-Terre is low limestone formation;
• most of the seven other islands are volcanic in origin;

Martinique:

mountainous with indented coastline; dormant volcano;

Mayotte:

generally undulating, with deep ravines and ancient volcanic peaks;

Reunion:

mostly rugged and mountainous; fertile lowlands along coast

• lowlands in north,
• uplands in center,
• Bavarian Alps in south

a narrow coastal lowland borders the Rock of Gibraltar

mountainous with ranges extending into the sea as peninsulas or chains of islands

mostly flat with low hills in southwest

urban; low hill

mostly flat to rolling plains; hills and low mountains on the Slovakian border

mostly flat to rolling interior plain surrounded by rugged hills and low mountains; sea cliffs on west coast

hills in north and south bisected by central valley

mostly rugged and mountainous; some plains, coastal lowlands

gently rolling plain with low, rugged hills along north coast

flat fluvial basin at an elevation of 400-700 m above sea level surrounded by several high mountain ranges with elevations of 2,000 to 2,500 m

low plain

mostly mountainous (Alps) with Rhine Valley in western third

• lowland,
• many scattered small lakes,
• fertile soil

• mostly gently rolling uplands with broad, shallow valleys;
• uplands to slightly mountainous in the north;
• steep slope down to Moselle flood plain in the southeast

• mostly low,
• rocky,
• flat to dissected plains;
• many coastal cliffs

rolling steppe, gradual slope south to Black Sea

• hilly,
• rugged,
• rocky

highly indented coastline with narrow coastal plain backed by rugged high limestone mountains and plateaus

mostly coastal lowland and reclaimed land (polders); some hills in southeast

• mountainous with deep basins and valleys;
• three large lakes, each divided by a frontier line;
• country bisected by the Vardar River

• glaciated;
• mostly high plateaus and rugged mountains broken by fertile valleys;
• small, scattered plains;
• coastline deeply indented by fjords;
• arctic tundra in north

mostly flat plain; mountains along southern border

the west-flowing Tagus River divides the country:

the north is mountainous toward the interior, while the south is characterized by rolling plains

central Transylvanian Basin is separated from the Moldavian Plateau on the east by the Eastern Carpathian Mountains and separated from the Walachian Plain on the south by the Transylvanian Alps

rugged mountains

• extremely varied;
• to the north, rich fertile plains;
• to the east, limestone ranges and basins;
• to the southeast, ancient mountains and hills

rugged mountains in the central and northern part and lowlands in the south

• a short southwestern coastal strip of Karst topography on the Adriatic;
• an alpine mountain region lies adjacent to Italy and Austria in the north;
• mixed mountains and valleys with numerous rivers to the east

large, flat to dissected plateau surrounded by rugged hills; Pyrenees Mountains in north

mostly flat or gently rolling lowlands; mountains in west

mostly mountains (Alps in south, Jura in northwest) with a central plateau of rolling hills, plains, and large lakes

mostly fertile plains (steppes) and plateaus, with mountains found only in the west (the Carpathians) or in the extreme south of the Crimean Peninsula

mostly rugged hills and low mountains; level to rolling plains in east and southeast

mostly low desert plain rising gently to low central escarpment

central plain with mountains to north and south; scattered but significant plains along southern coast

flat to rolling, sand- and dune-covered coastal plain