青海湖
Riyue Mountain (), known in Tibetan as Nyima Dawa La, is actually a mountain pass situated in Huangyuan County, Xining, Qinghai Province, China. The mountain pass is above sea level and separates the Qinghai Lake endorheic basin from the Huangshui River basin, a tributary of the Yellow River. The Daotang River () flows west from the pass into Qinghai Lake. The pass separates Qinghai Province into a pastoral zone in the west and an agricultural zone in the east.