The earth pool is located about 6 kilometers southeast of Tianchi, with an altitude of 1123 meters, a long axis of north-east direction, 150 meters long, 100 meters wide, an area of 1.25 hectares, a depth of 39- 50 meters, surrounded by dense and hard basalt, which is a typical Maqi Lake, named for its water surface below the ground. It is a lake formed by the accumulation of water in the crater formed by the late fall of lava lake.