At the 23rd session of the World Heritage Committee in Marrakech, Morocco, in 1999, Dazu Rock Carvings were finally presented to international experts. But due to limited application materials and language barriers, many experts could not fully understand the value of the Dazu grottoes and the site might fail to pass evaluation.

"I suddenly thought of my paintings of those grottoes which could explain everything," Guo says.

When the 23.15-meter-long scroll spread in front of the experts, they were fascinated by the number and aesthetic quality of the stone statues.

The carvings have attracted millions of visitors from home and abroad. Now, about 300 young Chinese researchers work at the museum.

"I have made those rock carvings rock again," Guo says.