Tourists visit the Huoshizhai National Geopark in Northwest China's Ningxia Hui autonomous region, May 19, 2017. The geopark is famous for its unique "Danxia" landform. Danxia, which means "rosy cloud", is a kind of 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. [Photo/Xinhua]