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 The project used of concrete (mainly for the dam wall), used 463,000 T of steel (enough to build 63 Eiffel Towers), and moved about of earth. The concrete dam wall is high above the rock basis. When the water level is at its maximum of above sea level, higher than the river level downstream, the dam reservoir is on average about in length and in width. It contains of water and has a total surface area of . On completion, the reservoir flooded a total area of of land, compared to the of reservoir created by the Itaipu Dam. The