Which water system does Tianzhu Songshan Ancient City belong to?

Internal water system. The water network system composed of all rivers, lakes and other water bodies in the basin is called water system. There stands a large-scale ancient city in the intermountain basin of Songshan Beach (Songshan Village, Songshan Township), which has been well preserved so far. It is the famous Songshan ancient city, also known as Shepherd City, 36 kilometers away from Tianzhu County. Songshan ancient city belongs to the internal water system, facing south and divided into two walls. The plane is in the shape of "Hui", and the city wall is basically complete.