Three Gorges primarily famous for its scenery, the Three Gorges region is also historically and culturally important in China. Many settlements and archaeological sites are in danger of being submerged by the rising reservoir of the Three Gorges Dam. Due to the lithological conditions of its different regions, the valleys of the Three Gorges are narrow in some areas and broad in others. Most narrow valleys occur in regions where there is limestone, which is relatively hard and resists erosion. However, water can flow along deep vertical fractures, eroding underneath. As the limestone bed is gradually undercut, parts of it fall into
Xiling Gorge the length of the entire Three Gorges region, is actually a series of four different gorges: Precious Sword; Horse Lung & Ox Liver; Soundless Bell; and Shadow Play Gorges. The Three Gorges Dam was constructed at Sāndòupíng in the middle of the Xiling Gorge. Before the construction of the Three Gorges Dam and Gezhouba Dam, Xiling was known for being the most dangerous of the three gorges to travel through, with frightening whirlpools and strong rapids. Since the construction of the dams, the river's depth has increased from in some areas below the dam, to well over throughout the reservoir's