Introduction to Tongtian River: Tongtian River was called "Yak River" in ancient times and became famous all over the world because it was included in "Journey to the West". This river is formed after the Tuotuo River and Dangqu merge in the Bayong area of ​​Nangji, 60 kilometers downstream of the Tuotuo River Bridge. The Tongtian River is the name of the Yangtze River that flows through Yushu Prefecture, passing through the wide valleys of the Tanggula Mountains and the Kunlun Mountains. middle.