Introduction to Black Lake: Black Lake is the largest among the three-color lakes, with an area of about more than 10,000 square meters. In rainy seasons, the water storage capacity can reach more than 20,000 cubic meters. It is in the shape of a "Z" and is surrounded by mountains. . Black Lake is called "Cuona" in Tibetan. It looks like ink from a distance, surrounded by mountains, and is unfathomable. The surrounding mountains are made of black rocks, which overflow into the bottom of the lake, making the water appear deep and black, hence the name "Black Lake". At the lower end of the Black Lake, the water passes through the cracks in the rocks and pours into the White Lake. The two lakes are connected, one big and one small, so they are also called "Mother and Son Lake".