Rising in the northern Angolan highlands, two rivers converge to form the Okavango River (known as the Kavango River in Namibia), one of the last free-flowing rivers in the world, which eventually empties into the sandy expanses of Botswana's Kalahari Desert.

An average of 10 million cubic meters of water annually floods nearly 18,000 square km of Kalahari, forming the Okavango Delta, the world's largest inland delta.