The Crescent Moon Spring, or Crescent Lake, is a lake in an oasis found south of Dunhuang city in Gansu Province. Known among locals as yueyaquan, the lake has an average depth of 4-5 meters, which had shrunk around the 1990s. The local government prevented the decline of the water level of the oasis by filling it up, thereby maintaining it as a popular attraction among tourists who are offered 4x4 and camel rides to reach the site.