Introduction to Da'an River: Da'an River runs north-south, starting from the lower end of Weigou in the north, passing through Xiaoheiyu Valley, Shuiliandong and Hongwan River and flowing into Huangshiya Reservoir, with a total length of 2.5 kilometers. The trees on both sides of the ditch are lush and leafy, and the bottom of the ditch is full of strange rocks. The two sides of the middle part of the ditch are as if carved by God's axe, and the colored stones are as picturesque and lifelike. They are a typical park of the Culaishan Global Geopark.