Botswana and 30°E. The country is predominantly flat, tending toward gently rolling tableland. Botswana is dominated by the Kalahari Desert, which covers up to 70% of its land surface. The Okavango Delta, one of the world's largest inland deltas, is in the northwest. The Makgadikgadi Pan, a large salt pan, lies in the north. The Limpopo River Basin, the major landform of all of southern Africa, lies partly in Botswana, with the basins of its tributaries, the Notwane, Bonwapitse, Mahalapye, Lotsane, Motloutse and the Shashe, located in the eastern part of the country. The Notwane provides water to the capital through
Kalahari Debate with merchant capital. They believe the San in the Kalahari are a classless society because they are actually the lower class of a greater Kalahari society. The revisionists believe the !Kung San were heavily involved in trade. They believe the San were transformed by centuries of contact with Iron Age, Bantu-speaking agro-pastoralists. This argues against the idea that they were a well-adapted hunter-gatherer culture, but instead advanced only through trade and help from nearby economies. When it comes to archaeological evidence, much work still has yet to be done. However, artifacts and ecofacts have been found at southern African sites