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