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)