South Africa’s surface area falls into two major physiographic categories: the interior plateau and the land between the plateau and the coast. Forming the boundary between these two areas is the Great Escarpment, the most prominent and continuous relief feature of the country. Its height above sea level varies from about 1 500 m in the southwest, to a height of just under 3 500m in the KwaZuluNatal Drakensberg. Inland from the escarpment lies the interior plateau, which is the southern continuation of the great African plateau stretching north to the Sahara Desert. The plateau itself is characterised by wide plains with an average height of 1 200 m above sea level. Between the Great Escarpment and the coast lies an area which varies in width from 80km to 240km in the east and south, and a mere 60km to 80km in the west.