It is at Puli township, Nantou county. This natural lake is about 19.39 ha. It separates in to north and south lake. The depth and the views are totally different. The south lake is deeper and dark, the north lake is clearer. The length is about 1300 meters. The legend says there are seven caves here. Every cave has the different meaning superstition and taboos. The seven caves are carp cave, shrimp cave, bat cave, eagle cave, dragon cave, turtle cave and centipede cave.