| Country | Terrain |
| Afghanistan | mostly rugged mountains; plains in north and southwest |
| Akrotiri | void |
| Albania | mostly mountains and hills; small plains along coast |
| Algeria | mostly high plateau and desert; some mountains; narrow, discontinuous coastal plain |
| American Samoa | five volcanic islands with rugged peaks and limited coastal plains, two coral atolls (Rose Island, Swains Island) |
| Andorra | rugged mountains dissected by narrow valleys |
| Angola | narrow coastal plain rises abruptly to vast interior plateau |
| Anguilla | flat and low-lying island of coral and limestone |
| Antarctica | about 98% thick continental ice sheet and 2% barren rock, with average elevations between 2,000 and 4,000 meters; mountain ranges up to nearly 5,000 meters; 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 |
| Antigua and Barbuda | mostly low-lying limestone and coral islands, with some higher volcanic areas |
| Arctic Ocean | central surface covered by a perennial drifting polar icepack that, on average, is about 3 meters thick, although pressure ridges may be three times that thickness; clockwise drift pattern in the Beaufort Gyral Stream, but nearly straight-line movement from the New Siberian Islands (Russia) to Denmark Strait (between Greenland and Iceland); the icepack is surrounded by open seas during the summer, but more than doubles in size during the winter and extends to the encircling landmasses; the ocean floor is about 50% continental shelf (highest percentage of any ocean) with the remainder a central basin interrupted by three submarine ridges (Alpha Cordillera, Nansen Cordillera, and Lomonosov Ridge) |
| Argentina | rich plains of the Pampas in northern half, flat to rolling plateau of Patagonia in south, rugged Andes along western border |
| Armenia | Armenian Highland with mountains; little forest land; fast flowing rivers; good soil in Aras River valley |
| Aruba | flat with a few hills; scant vegetation |
| Ashmore and Cartier Islands | low with sand and coral |
| Atlantic Ocean | surface usually covered with sea ice in Labrador Sea, Denmark Strait, and coastal portions of the Baltic Sea from October to June; clockwise warm-water gyre (broad, circular system of currents) in the northern Atlantic, counterclockwise warm-water gyre in the southern Atlantic; the ocean floor is dominated by the Mid-Atlantic Ridge, a rugged north-south centerline for the entire Atlantic basin |
| Australia | mostly low plateau with deserts; fertile plain in southeast |
| Austria | in the west and south mostly mountains (Alps); along the eastern and northern margins mostly flat or gently sloping |
| Azerbaijan | 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) in west; Baku lies on Abseron Yasaqligi (Apsheron Peninsula) that juts into Caspian Sea |
| Bahamas, The | long, flat coral formations with some low rounded hills |
| Bahrain | mostly low desert plain rising gently to low central escarpment |
| Bangladesh | mostly flat alluvial plain; hilly in southeast |
| Barbados | relatively flat; rises gently to central highland region |
| Belarus | generally flat and contains much marshland |
| Belgium | flat coastal plains in northwest, central rolling hills, rugged mountains of Ardennes Forest in southeast |
| Belize | flat, swampy coastal plain; low mountains in south |
| Benin | mostly flat to undulating plain; some hills and low mountains |
| Bermuda | low hills separated by fertile depressions |
| Bhutan | mostly mountainous with some fertile valleys and savanna |
| Bolivia | rugged Andes Mountains with a highland plateau (Altiplano), hills, lowland plains of the Amazon Basin |