There are trough basins in the Nanling, the most of the western basins in Nanling Mountains are composed of limestone, where karst regions are located. the most of the eastern basins are made up of red sandstone, where are danxia landform areas. The Nanling are boundaries between the four provinces of Guangdong, Guangxi, Hunan and Jiangxi, and also the cultural boundaries, on the south of the mountains are Lingnan culture area.