The topography of Nanning is the basin area with a large-scale river valley in the center. The mouth of the basin is in the east and mountains around it from the south, north and the west sides. High peaks and low hills standing in the north, seven hills in the south and Fenghuang Mountain in the west form a long river valley basin starting from the west Fenghuang Mountain to the east Qingxiu Mountain. The center of the basin is the gathering place of all rivers as Youjiang River from the northwest, Zuojiang River from southwest, Liangfengjiang River from the south and Xinxujiang River from the north. In the central part of the basin, the hills in the south and north are close to the river bank and make a natural boundary line separating the long river valley and basin into two small basins. One is the Yongjiang river valley basin with the city proper as the center, the other is an eroded and corroded basin around Tanlou Town.