Namibia, officially the Republic of Namibia (Afrikaans: Republiek van Namibië, German: Republik Namibia (help·info)), is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. Although it does not border with Zimbabwe, less than 200 meters of riverbed (essentially the Zambia/Botswana border) separates them at their closest points. It gained independence from South Africa on 21 March 1990, following the Namibian War of Independence. Its capital and largest city is Windhoek. Namibia is a member state of the United Nations (UN), the Southern African Development Community (SADC), the African Union (AU), and the Commonwealth of Nations.
The dry lands of Namibia were inhabited since early times by Bushmen, Damara, and Namaqua, and since about the 14th century AD by immigrating Bantu who came with the Bantu expansion. It became a German Imperial protectorate in 1884 and remained a German colony until the end of World War I. In 1920, the League of Nations mandated the country to South Africa, which imposed its laws and, from 1948, its apartheid policy.
In physical geography, a dune is a hill of sand built either by wind or water flow. Dunes occur in different forms and sizes, formed by interaction with the flow of air or water. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind. The valley or trough between dunes is called a slack. A "dune field" is an area covered by extensive sand dunes. Large dune fields are known as ergs.
Some coastal areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach. In most cases the dunes are important in protecting the land against potential ravages by storm waves from the sea. Although the most widely distributed dunes are those associated with coastal regions, the largest complexes of dunes are found inland in dry regions and associated with ancient lake or sea beds.