Zhangye Danxia Geopark is a national scenic area in Gansu Province, China. The Danxia landform was formed by red sandstone (or "redstone") being transformed into colorful hills and cliffs through the process of weathering and erosion. It lies within a much larger area of distinctive landscape features known as the Red Basin (赤壑), which formed as the result of continental collision between the Chinese craton and the Eurasian continent.