Tourists view the scenery of Danxia landform at the Danxia Scenic Area in Zhangye City, northwest China's Gansu Province, July 27, 2013. Danxia, which means "rosy cloud", is a special landform formed from reddish sandstone that has been eroded over time into a series of mountains surrounded by curvaceous cliffs and many unusual rock formations. (Xinhua/Wang Song)