and
mangrove swamps

Tuvalu
very low-lying and narrow coral atolls

Uganda
mostly plateau with rim of mountains

Ukraine
most of Ukraine consists of fertile plains (steppes) and
plateaus, mountains being found only in the west (the Carpathians),
and in the Crimean Peninsula in the extreme south

United Arab Emirates
flat, barren coastal plain merging into rolling
sand dunes of vast desert wasteland; mountains in east

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

United States
vast central plain, mountains in west, hills and low
mountains in east; rugged mountains and broad river valleys in
Alaska; rugged, volcanic topography in Hawaii

United States Pacific Island Wildlife Refuges
low and nearly level
sandy coral islands with narrow fringing reefs that have developed
at the top of submerged volcanic mountains, which in most cases rise
steeply from the ocean floor

Uruguay
mostly rolling plains and low hills; fertile coastal lowland

Uzbekistan
mostly flat-to-rolling sandy desert with 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

Vanuatu
mostly mountainous islands of volcanic origin; narrow
coastal plains

Venezuela
Andes Mountains and Maracaibo Lowlands in northwest;
central plains (llanos); Guiana Highlands in southeast

Vietnam
low, flat delta in south and north; central highlands;
hilly, mountainous in far north and northwest

Virgin Islands
mostly hilly to rugged and mountainous with little
level land

Wake Island
atoll of three low coral islands, Peale, Wake, and
Wilkes, built up on an underwater volcano; central lagoon is former
crater, islands are part of the rim

Wallis and Futuna
volcanic origin; low hills

West Bank
mostly rugged dissected upland, some vegetation in west,
but barren in east

Western Sahara
mostly low, flat desert with large areas of rocky or
sandy surfaces rising to small mountains in south and northeast

World
the greatest ocean depth is the Mariana Trench at 10,924 m in
the Pacific Ocean

Yemen
narrow coastal plain backed by flat-topped hills and rugged
mountains; dissected upland desert plains in center slope into the
desert interior