Restorers carry out restoration work inside Cave 30 of the Maijishan Grottoes. [Photo/Gansu Daily]

The Maijishan Grottoes in Tianshui, Gansu province, a complex of 221 caves first carved over 1,600 years ago, stand as one of China's four great grottoes. However, the rainy, humid local climate constantly threatens its sculptures and murals with hollowing, cracking, and salt efflorescence.

For 59-year-old Mu Changyou, preservation is a test of patience. "Restoration is extremely meticulous work. Months or even years of effort might go into preventing a single crack from expanding," he said. 

Over the course of four decades, Mu has helped restore 36 caves and led the restoration of 26 others, reviving over a thousand statues. He began as a laborer and is now a senior restorer at the Maijishan Grottoes Art Research Institute. "We aren't creating something new but integrating modern materials with artifacts from more than 1,000 years ago." 

The institute, originally founded in 1953, has consistently worked to protect the site. "Seventy years of continuous effort have allowed us to build a dedicated restoration team," said Ma Qian, head of the conservation research office.

Today, technology enhances these efforts in new ways. Each cave is equipped with instruments that monitor temperature, humidity, and carbon dioxide levels in real time, enabling early risk detection. Research teams have also used high-precision photography and 3D scanning to digitally document over 10 caves in detail, forming the foundation for precise 3D models. These digital assets will allow full-scale replicas of certain caves and sculptures to be created, sharing Maijishan's beauty with audiences far and wide.