The Danxia landforms are the various landscapes found in southeast and southwest China which consist of steep cliffs naturally decorated with red 'beds'. Theses landforms are unique amongst all rock formations in the world. They are formed from red sandstone which date back largely to the Cretaceous period. Peculiar to the landscape of Danxia is the development of numerous caves of varying sizes, shapes and depths. Six of the formations in 2010 were pronounced to be UNESCO World Heritage Sites.