Introduction to the reservoir dam: The location of the reservoir dam was originally Xishuiyuguan. Because the pass is located in the upper reaches of the Huaijiu River, in the valley on the west side of Huanghuacheng, and the water in the valley flows from west to east, it is called Xishui Yuguan. The main body of the dam is composed of five holes, which represents the five elements (metal, wood, water, fire, and earth), and also means the harvest of grains (rice, millet, millet, wheat, and beetroot).