Heilongchi Introduction: Heilongchi is located in a mountain recess at an altitude of 3,800 meters, with a water surface of more than 40 acres. It is named because the water is clear and slightly black. The water of Heilong Pond is often covered with dense fog, but sparkles on sunny days. There are meadows and rhododendron forests beside the pond. The locals are very mysterious about it. There is a saying that "the mountain is not bullied by the water". In winter, ice can form more than a foot thick, and yaks can walk on it.