Zambia tributaries rise in Angola's central highlands. The edge of the Cuando River floodplain (not its main channel) forms Zambia's southwestern border, and via the Chobe River that river contributes very little water to the Zambezi because most is lost by evaporation. Two of the Zambezi's longest and largest tributaries, the Kafue and the Luangwa, flow mainly in Zambia. Their confluences with the Zambezi are on the border with Zimbabwe at Chirundu and Luangwa town respectively. Before its confluence, the Luangwa River forms part of Zambia's border with Mozambique. From Luangwa town, the Zambezi leaves Zambia and flows into Mozambique, and
South Africa–Zimbabwe border boundaries of the South African Republic (the Transvaal Republic). The South African Republic subsequently became the Transvaal Colony and then part of the Union of South Africa, while north of the Limpopo Matabeleland became part of Southern Rhodesia which became Zimbabwe. There is a single crossing at Beit Bridge, where the South African N1 highway and the Zimbabwean A6 highway are joined by the Alfred Beit Road Bridge. A separate bridge carries a railway line, which is connected to Pretoria in South Africa and to Rutenga and Bulawayo in Zimbabwe. South Africa–Zimbabwe border The border between South Africa and Zimbabwe