In pics: Maiji Mountain Grottoes in Tianshui, China's Gansu

Aerial photo taken on Dec. 26, 2019 shows the Maiji Mountain Grottoes after snow in Tianshui, northwest China's Gansu Province. The Maiji Mountain Grottoes is one of the four most famous grottoes in China with 221 grottoes preserved at present. (Xinhua/Ma Ning)