Changhai is a long sea of Jiuzhaigou. It is a few kilometers long and has an ink blue color and an "S" shape. The waters of the sea are dense, and at first glance, the spectacular snow peaks and the typical glacier landscape are bathed in blue sky and white clouds. There is no water outlet around the Changhai Sea, and the water comes from snow melting in the mountains. The strange thing is that the Changhai will never dry up and will not overflow the embankment. Therefore, the Tibetans call it the "Gourd gourd with dissatisfaction and leaks."