Ancient grottoes thrive via innovative measures

The meeting between 100,000 millennium-old cliff carvings and modern technologies, like 3D scanning and holographic projection, has proved a fruitful interaction between past and present in Anyue county, Southwest China's Sichuan province.

Previously, people had to venture into the deep countryside to witness these cultural relics from the Tang and Song dynasties. Today, a 7.13-hectare digital exhibition center makes the carvings more accessible to visitors.

In the exhibition hall at this center, innovative technologies such as mapping projection, gesture sensing, brainwave interaction and AI algorithms breathe vivid new life into age-old Buddhas and murals. Notably, a four-panel immersive cinema and a 3D-8K dome theater offer visitors excellent audiovisual experiences.

Since its trial operation in May this year, the Anyue Grottoes Digital Exhibition Center, a culture-and-tourism complex dedicated to digital conservation, display and interaction of grottoes, has already drawn more than 150,000 visitors -- with daily visits topping 3,000 during the 2025 summer holiday period.

"Anyue enjoys exceptional geography and geology," said a staff member at the Anyue Grottoes Digital Exhibition Center.

Rolling hills dominate the landscape in Anyue, and the bedrock is mostly light-brown or grey sandstone of moderate hardness, which is widely distributed. The county also has abundant resources when it comes to gravel and cliffs. All these characteristics are very suitable for large-scale stone carvings.

Anyue is home to nearly 500 grotto-temple sites -- ten of which are listed as national key cultural relics protection sites -- and hosts more than 100,000 cliff carvings and almost 400,000 characters featured in cliff sutras.

Hailed by scholars as the pinnacle of China's late-period grotto art endeavors and the definitive example of southern Chinese grottoes, the Anyue grottoes have been inscribed on China's national list of intangible cultural heritage.

"Every township here has grotto statues," said Xie Yang, head of the Anyue Grottoes Research Institute. However, these grottoes face risks posed by water damage, weathering and fissures.

Carved into red sandstone, the Anyue grottoes are highly vulnerable to weathering and erosion. Compounded by southern China's humid climate, the grottoes have long been plagued by destructive natural factors such as water runoff, invasive root systems and wind abrasion.

Many of the grotto temples across the county are located in remote rural areas and hills -- posing huge challenges in terms of daily inspection, protection, management and the coverage of protective facilities, according to Xie.

In 2018, the county issued a local regulation to protect the grottoes. Over the years, Anyue has carried out more than 20 cross-departmental inspections and eliminated three major hidden dangers in the cases of facilities which had collapsed or been damaged due to years of disrepair.

The county has also cooperated with Peking University, Zhejiang University and Sichuan University in carrying out archaeological investigations and research to enhance scientific capabilities and technical levels regarding protection and utilization of grottoes.

The protection of grottoes is an interdisciplinary project, said Xie. "Thus we must establish a multidisciplinary cooperation mechanism pooling the talent of petrology, history and archaeology."

Xie said her institute has employed 17 researchers with master's degrees and four university graduates majoring in cultural relics.

"We have about 3,500 guardians of cultural relics," Xie revealed. "And we make sure that every grotto site has a guardian."

Additionally, Anyue has set up a dedicated fund for the conservation of grotto relics and rolled out a comprehensive security upgrade, equipping 177 key grotto-temple sites with round-the-clock video surveillance.

Anyue has promised to continue its tech-driven conservation efforts, including the use of high-precision 3D scanning and digital modeling.

"We will also establish a database for the grotto temples, in order to create permanent digital archives for cultural relics that can be used for exhibition, monitoring and virtual restoration," Xie noted.

She disclosed that they are making preparations for micro-trace extraction to be applied to the sutras.

Some of the digital achievements of Anyue's grotto protection efforts will be showcased on a mini-program by the end of this year, allowing netizens to explore these stone masterpieces up close, Xie added.