The project, which started on April 1, involves 185.47 square meters of murals in Xumishan's grottoes numbered 1, 48, 50 and 51, Wang said.
Located in Guyuan's Yuanzhou district, the Xumishan Grottoes that have a history of more than 1,500 years and are one of the 10 major ancient grottoes in China.
They are listed as key cultural relics and have been under State protection since 1982.