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
Lost City of the Kalahari any signs of construction in the area. A. J. Clement researched the story in 1964 and advanced a new theory. Clement claimed his study of Farini's description of his route highlighted inconsistencies in Farini's story. Clement concluded that Farini went deep into Southern Africa, but he never actually went to the heart of the Kalahari where he claimed the Lost City was sited. To test this premise Clement explored what he regarded as Farini's true route and discovered a set of monumental rocks, resembling walls. Clement concluded that Farini's 'lost city' was shown to exist but as a natural formation.