"They have to best fit the Guanyin statue, which is of sandstone texture, as well as take into account high temperature and humid environment," Chen explains, adding that every decision and move were made based on studies of the statue and related history and scientific papers.

For example, she and her team used to go to Sichuan, Hebei and Shandong provinces to study rock carvings, trying to draw inferences for mending the statue's broken right hand.

"It was repaired by the ancients, but was inconsistent to the original," Chen says.

She then proposed to create a detachable hand based on the symmetric features of the statue, because there is still one minor inconsistency in the angle of the remaining bracelet buckle.

"Therefore, future fixes can be easier to be applied, when more is discovered," Chen says.

Now, the restored statue looks solemn and shines, and has become a major attraction.

The Academy of Dazu Rock Carvings has also worked with international organizations to repair local rock carvings.

At Shuchengyan site in the district's Zhongao town, a cave temple has recently finished preliminary restoration, thanks to joint efforts between a cultural heritage cluster from Italy and the Academy of Dazu Rock Carvings.

The project started in 2018, and a series of experiments and analysis were then conducted by both sides on gold foil, paint, rock and microorganisms, as well as repairing techniques, for a year before restoration eventually kicked in.

"The temple was very popular in the old times and visited a lot by locals," says Ruan Fanghong, an official with the project.

As a result, many rock carvings were damaged.

The two sides applied synthetic enzymes to remove impurities from the paint, and used polyvinyl alcohol to paste the gold foils back.

"Now, several years have passed, and the restored parts have maintained very well," Ruan says.

In the last decade, 246 million yuan ($33.1 million) has been put into 24 restoration projects in Dazu, according to local authorities.

In addition to the major rock carving sites, a comprehensive conservation and research project has been launched since 2020 to cover more than 60 medium- and small-sized sites.

According to the Dazu academy's plan, about 700,000 yuan will be allocated for the renovation of each site. By 2025, all potential hazards to these medium- and small-sized sites will be addressed.

After years of hard work they are on the homestretch of completion, Chen says.

"We'll lay more of a focus on restoring them to the original beauty in the future, while keeping them under close watch for their safety."