Photo taken on Nov. 19, 2020 shows Grotto No. 13 of Tiantishan Grottoes in Wuwei City, northwest China's Gansu Province. Tiantishan Grottoes are believed to be built as early as 1,600 years ago. (Xinhua/Du Zheyu)
In pics: Tiantishan Grottoes in Wuwei City, Gansu
Source: Xinhua| 2020-11-20 15:56:10|Editor: huaxia