word | | Terrain |
| Andes | Peru | western coastal plain (costa), high and rugged Andes in center (sierra), eastern lowland jungle of Amazon Basin (selva) |
| Andes | Venezuela | Andes Mountains and Maracaibo Lowlands in northwest; central plains (llanos); Guiana Highlands in southeast |
| Antarctic | Antarctica | ... 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 ... |
| Antarctic | Southern Ocean | ... to 5,000 m over most of its extent with only limited areas of shallow water; the Antarctic continental shelf is generally narrow and unusually deep, its edge lying at depths of 400 ... |
| Antarctica | Pacific Ocean | ... the Bering Sea and Sea of Okhotsk in winter; in the southern Pacific, sea ice from Antarctica reaches its northernmost extent in October; the ocean floor in the eastern Pacific is dominated ... |
| Anti | Lebanon | narrow coastal plain; El Beqaa (Bekaa Valley) separates Lebanon and Anti-Lebanon Mountains |
| any | Arctic Ocean | ... 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 ... |
| Apsheron | Azerbaijan | ... 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 |
| Arabian | Yemen | narrow coastal plain backed by flat-topped hills and rugged mountains; dissected upland desert plains in center slope into the desert interior of the Arabian Peninsula |
| Araks | 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 ... |
| Aral | Uzbekistan | ... dunes; broad, flat intensely irrigated river valleys along course of Amu Darya, Syr Darya (Sirdaryo), and Zarafshon; Fergana Valley in east surrounded by mountainous Tajikistan and Kyrgyzstan; shrinking Aral Sea in west |