Tianchi (Chinese: 天池; pinyin: tiānchí) is an alpine lake in Xinjiang, Northwest China, situated at 43°53′9.7″N 88°7′56.6″E / 43.886028°N 88.132389°E. The name (天池) literally means "Heaven Lake" or "Heavenly Lake" and can refer to several lakes in mainland China and Taiwan. This Tianchi lies on the north side of the Bogda Shan range of the Tianshan Mountains, about 30 kilometres (19 mi) south of Fukang City and 45 kilometres (28 mi) east (straight-line distance) of Ürümqi. (Bogda is a Mongolian word, meaning "God".) It is an alpine drift lake shaped in the Quaternary Glacier period.
Formerly known as Yaochi (Jade Lake), it was named Tianchi in 1783 by Mingliang, the Qing Commander of Urumqi Command.
The lake is 2,000 metres (6,600 ft) above sea level, covering 4.9 square kilometres (1.9 sq mi), 105 metres (344 ft) deep at the deepest point.