While visiting the cave art site at the Yungang Grottoes in Datong, Xi stressed the protection of the Yungang Grottoes as they are a "treasure of human civilization".

The Yungang Grottoes represent the characteristics of Chinese culture and the history of cultural exchanges between China and other countries, Xi said, adding that protection of the site should be a top priority.

With 45 major caves and more than 51,000 statues, the 1,500-year-old Yungang Grottoes were listed as a UNESCO World Heritage Site in 2001.

While inspecting Gansu province in August 2019, Xi visited the Mogao Grottoes to learn about the site's history and cultural heritage protection work.