For those who can's visit, grottoes come to them

Thanks to four decades of digitization, residents from Wuhan can now observe the ancient wonders from home during the four-month exhibition from May 18 to Sept 18. And it's free.

"I have been to Dunhuang at least 50 times and always spend a whole day inside the caves," Huang said, noting that his ankles often hurt in winter because of that.

"In the early years, the biggest challenge was not the freezing cold but lack of appropriate equipment," he recalled.