The topography of Hainan Island is high in the middle, low around and high in the middle, showing dome-shaped mountain topography. The highest peaks, Wuzhishan (1867m) and Ying Ge Ridge (18 1 1 m), are the uplift cores, and gradually descend to the periphery. The annular layered landform is composed of mountains, hills, terraces and plains, showing a cascade structure. Most of the relatively large rivers in Hainan Island originate from the central mountainous areas, forming a radial water system. Hainan is the only inhabited area of Li nationality in China, and Li nationality has unique national culture and customs.