The Democratic Republic of the Congo (French: République démocratique du Congo), is a country in central Africa with a small length of Atlantic coastline. It is the third largest country (by area) in Africa. In order to distinguish it from the neighbouring Republic of the Congo, the Democratic Republic of the Congo is often referred to as DR Congo, DRC, or RDC, or is called Congo-Kinshasa after the capital Kinshasa (in contrast to Congo-Brazzaville for its neighbour). The name "Congo" refers to the river Congo, also known as the river Zaire. (The river name Congo is related to the name of the Bakongo ethnic group). The Democratic Republic of the Congo was formerly, in turn, the Congo Free State, Belgian Congo, Congo-Léopoldville, Congo-Kinshasa, and Zaire (or Zaïre in French). Though it is located in the Central African UN subregion, the nation is economically and regionally affiliated with Southern Africa as a member of the Southern African Development Community (SADC). DR Congo borders the Central African Republic and Sudan on the North; Uganda, Rwanda, and Burundi on the East; Zambia and Angola on the South; the Republic of the Congo on the West; and is separated from Tanzania by Lake Tanganyika on the East. The country enjoys access to the ocean through a 40-kilometre (25 mile) stretch of Atlantic coastline at Muanda and the roughly nine-kilometre wide mouth of the Congo river which opens into the Gulf of Guinea.