Tibet is on a high plateau--the Plateau of Tibet--surrounded by enormous mountain masses. The relatively level northern part of the plateau is called the Ch'iang-t'ang; it extends more than 800 miles (1,300 kilometres) from west to east at an average elevation of 15,000 feet (4,500 metres) above sea level. The Ch'iang-t'ang is dotted with brackish lakes, the largest of these being Lakes Ch'i-lin and Na-mu. There are, however, no river systems there. In the east the Ch'iang-t'ang begins to descend in elevation. The mountain ranges in southeastern Tibet cut across the land from north to south, creating meridional barriers to travel and communication. In central and western Tibet the ranges run from northwest to southeast, with deep or shallow valleys forming innumerable furrows.

The Ch'iang-t'ang is bordered on the north by the Kunlun Mountains, with the highest peak, Mu-tzu-t'a-ko (on the Tibet-Nepal border), reaching 25,338 feet (7,723 metres). The western and southern border of the Plateau of Tibet is formed by the Himalayan mass; the highest peak is Mount Everest, which rises to 29,028 feet (8,848 metres) on the Tibet-Nepal border. North of Ma-fa-mu Lake (Mapam Lake; conventional Manasarowar) and stretching eastward is the Kailas (Kang-ti-ssu) Range, with clusters of peaks, several exceeding 20,000 feet. This range is separated from the Himalayas by the Brahmaputra River, which flows across southern Tibet and cuts south through the mountains to India.