Chengguan synonymous referred to as Chamdo or Qamdo, population in 1999 about 86,280, is a major town in the historical region of Kham in the eastern Tibet Autonomous Region of China. The seat of Karub District and Chamdo, it is Tibet's third largest city after Lhasa and Shigatse. It is located about (as the crow flies) from Lhasa. On the road the distance covers (southern route) or (northern route). It is at an altitude of at the confluence of the rivers Za Qu and Ngom Qu which form the Mekong.