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
Three Gorges Dam vulnerable hinged type, which, if damaged, could temporarily render the entire flight unusable. As there are separate sets of locks for upstream and downstream traffic, this system is more water efficient than bi-directional staircase locks. In addition to the canal locks, there is a ship lift, a kind of elevator for vessels. The ship lift can lift ships of up to 3,000 tons. The vertical distance traveled is 113 metres, and the size of the ship lift's basin is 120×18×3.5 metres. The ship lift takes 30 to 40 minutes to transit, as opposed to the three to four hours for