History

　　Qinghai Lake is very famous in history, which is also important military defense. Date back to Han Dynasty, Qiang people swam in this lake, which was called “Xianbeiqiang Sea”. In Han records, it was also called Xian Lake, Xian Sea, or West Sea. Nowadays, on the northeast of Qinghai Lake there is a famous West Sea County Site called “Triangle City”, which was built in 4AD. Although most part is broken, the main structure still remains. Other contemporary sites include Gahai City in Haiyan County, Xiangyang City and Fusi City in Gangcha County. The exploration of these ancient cities showed prosperity of Qinghai Lake area in the history.