High Quality Content by WIKIPEDIA articles! The Okavango River is a river in southwest Africa. It is the fourth-longest river system in southern Africa, running southeastward for 1,600 km (1,000 miles). It begins in Angola, where it is known as the Cubango River. Further south it forms part of the border between Angola and Namibia, and then flows into Botswana, draining into the Moremi Game Reserve. Before it enters Botswana, the river drops four meters, across the full 1.2 km-width of the river, in a series of rapids known as Popa Falls, visible when the river is low, as during the dry season.