Lake Tianchi (天池) is located within the Changbai Mountains of Jilin Province, in northeast China, not far from the North Korean border.

It has been recognized as the highest volcanic lake in the world. At an altitude of 2,189.1 meters, the crater lake covers an area of 9.82 square kilometers with a south-north length of 4.85 kilometers and east-west length of 3.35 kilometers.

The lake is allegedly hosting the Lake Tianchi Monster. In ancient Chinese literature, Tianchi also refers to Nanming (?) (南冥 some translate to southern sea). It is unknown if the Monster and legendary Kun are related.

The name Tianchi literally means heavenly pond, and hence it is used quite commonly for various bodies of water in China. Some better known Tianchi include those in (長白山) Jilin, (天山) Xinjiang, (梨山) Taiwan etc.