Tourists enjoy themselves on the Caka salt lake in Wulan County, northwest China's Qinghai Province, Aug. 21, 2015. The Caka salt lake is one of the most famous natural tourism destinations in Qinghai for Chinese tourists. The lake, with an altitude of 3,100 meters, is ten times as large as the West Lake in east China's Hangzhou City. The history of salt mining here can date back to over 3,000 years ago. (Xinhua/Wu Gang)
