Located in southwest China's Sichuan Province, the Long Lake in Jiuzhaigou is the highest-altitude and longest lake in the scenic area. It is also the source of the Jiuzhaigou water system. In Tibetan, it is known as the "treasure gourd that never fills nor drains." Backed by the perpetually snow-capped peak of the Min Mountains, the lake is fed by melting snow and ice from the high mountains. Its unique geological structure makes it one of the most mysterious lakes in Jiuzhaigou.