Three distinct geographical regions, demarcated by ascending altitude, extend approximately north-south across Lesotho. The western quarter of the country is a plateau averaging 1,500 to 1,850 m (4,900–6,100 ft). The soil of this zone is derived from sandstone and, particularly in the westernmost region, is poor and badly eroded. The remainder of the country is highland. A zone of rolling foothills, ranging from 1,800 to 2,200 m (5,900– 7,200 ft), forms the border between the lowlands and the mountains in the east.
The Drakensberg Range forms the entire eastern and southeastern border. A spur of this range, the Maluti Mountains, runs north and south. Where it joins the Drakensberg Range there is a high plateau between 2,700 and 3,200 m (8,900– 10,500 ft) in elevation. The highest point is Thabana Ntlenyana, 3,482 m (11,425 ft), in the east. The rich volcanic soils of the foothills and mountains are some of the best in the country.
The sources of two of the principal rivers of South Africa, the Orange and the Tugela, are in these mountains. Tributaries of the Caledon River, which forms the country's western border, also rise here. The Orange and Caledon rivers, together with their tributaries, drain more than 90% of the country.