The Namib Desert in Namibia is considered the world's oldest desert. It covers more than 102,248 square miles (270,000 square kilometers) of the southwestern edge of the African continent. It also has the distinction of having the highest sand dunes in the world. Some of them rise to more than 1,300 feet (400 meters). Namibia, officially the Republic of Namibia, is a country in southern Africa on the Atlantic coast. It shares borders with Angola and Zambia to the north, Botswana to the east, and South Africa to the south. It gained independence from South Africa in 1990 and its capital city is Windhoek (German: Windhuk).