North of the Swartberg and up to the escarpment lies the Great Karoo, with the borders defined as the Kougaberg and Swartberg in the south; the Sederberg, the Koue Bokkeveldberg and the Groot Winterhoekberg in the west; the Roggeveldberg, Nuweveldberg, Sneeuberg, Renosterberg and Suurberg in the north; and a line roughly from the Suurberg southwards along the Tarka River to the southern Suurberg and then westwards to the convergence of the Groot and Bobbejaan Rivers. The eastern part between the Sondag and Vis Rivers, north of the Suurberg, is called the Cape Middlelands.
It is a dry region, drained by the Dwyka, Gamka and Buffel Rivers, which are all tributaries of the Gouritz River.