Lhasa is a prefecture-level city, formerly a prefecture until 7 January 1960, one of the main administrative divisions of the Tibet Autonomous Region of China. It covers an area of 29,274 square kilometres of rugged and sparsely populated terrain. The consolidated prefecture-level city is divided into five mostly rural counties and three partially urban districts Chengguan District, Doilungdêqên District, and Dagzê District, which contain the main urban area of Lhasa.
The prefecture-level city roughly corresponds to the basin of the Lhasa River, a major tributary of the Yarlung Tsangpo River. It lies on the Lhasa terrane, the last unit of crust to accrete to the Eurasian plate before the continent of India collided with Asia about 50 million years ago and pushed up the Himalayas. The terrane is high, contains a complex pattern of faults and is tectonically active. The temperature is generally warm in summer and rises above freezing on sunny days in winter. Most of the rain falls in summer. The upland areas and northern grasslands are used for grazing yaks, sheep and goats, while the river valleys support agriculture with crops such as barley, wheat and vegetables.