A hiker walks at a Danxia landform geopark near Zhangye, northwest China's Gansu Province, April 11, 2011. 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/Gao Jianjun)