The Kalahari is a vast semi-arid sandy savanna in Southern Africa, covering much of Botswana and parts of Namibia and South Africa. While often called a desert, it receives more rainfall than a typical 'true' desert (between 110–190 millimeters annually), allowing it to support a variety of plant life including acacias and grasses. It is characterized by vast areas covered by red sand without permanent surface water. The only permanent river that flows through it is the Okavango, which drains into a delta in the northwest, forming the Okavango Delta—a massive inland wetland that attracts incredible wildlife. The Kalahari is the ancestral home of the San people, who have lived there as hunter-gatherers for tens of thousands of years. The region is also famous for its 'black-maned' lions and large herds of gemsbok and springbok that have adapted to its dry conditions.