A tourist views the thangka painting inside the North Matisi Grottoes, in Sunan Yugur autonomous county of Zhangye, Northwest China's Gansu province, on Oct 18, 2024. [Photo by Yang Xiaoyu/chinadaily.com.cn]

Most of the grottoes were chiseled into cliffs, such as the North Matisi Grottoes, which were carved into a 100-meter-high cliff. The 21 caves are arranged in seven stories, with statues in every story, of both Tibetan Buddhism and Chinese Buddhism. Visitors have to climb narrow stone stairs to see the top grotto's Bodhisattva Lyudumu in a shrine.