
Tourists visit the Dunhuang Yardang National Geopark in Dunhuang, northwest China's Gansu Province, May 24, 2015. (Photo: Xinhua/Wang Song)

Tourists visit the Dunhuang Yardang National Geopark in Dunhuang, northwest China's Gansu Province, May 24, 2015. (Photo: Xinhua/Wang Song)











