A robot shaves foam polystyrene to reproduce a Buddhist statue at the Mogao Caves in Dunhuang, China. (Provided by Tokyo University of the Arts)

DUNHUANG, China--Japanese researchers are working to "clone" statues and murals at more than 100 grottoes in a stunning Buddhist cave complex here to save the ancient works of art from the teeming number of visitors to the UNESCO World Heritage site each year.

They are also repairing statues that were shoddily touched up by amateurs in past centuries as part of efforts to restore the Mogao Caves to the splendor they boasted more than 1,000 years ago.

Using its proprietary “cultural property cloning” technology, Tokyo University of the Arts is helping to reproduce many of the grottoes in the site that was a major stop for pilgrims and traders on the Silk Road.

The joint Japan-China project is intended to prevent further degradation of the noted World Heritage site on the Silk Road by allowing the rapidly surging number of visitors to gaze at copied grottoes instead of the actual ones.

The university is providing its expertise to the Dunhuang Research Academy in China to create faithful reproductions of historic structures by combining manual skills with digital technology.

It is the first time for the university to share the patented cultural property copying technology with an institution outside of Japan, according to university officials.

The Mogao Caves, consisting of 735 grottoes on a sheer cliff in suburban Dunhuang in what is now China's Gansu province, were created over 1,000 years from the fourth century.

Dunhuang flourished as an oasis town along the Silk Road.

The Mogao Caves are one of the largest Buddhist heritage sites in the world. They were granted UNESCO World Cultural Heritage status in 1987.

Significant sacred texts and numerous other Buddhist documents were discovered in 1900 in the so-called Library Cave, which is believed to have been walled up in the 11th century.

According to the Dunhuang Research Academy, the Japanese university’s technique will be combined with conventional copying and virtual reality technologies to replicate 138 grottoes.

The site for the copycat caves that will serve as a tourism center to better respond to visitor needs has already been selected, and construction funds raised. It is expected to open in a few years.


With China experiencing a tourism boom, the number of visitors to the Mogao Caves hit nearly 2 million last year, up 2.5-fold from 15 years before.

As carbon dioxide in the breath from the hordes of visitors alone has damaged and discolored the surface of the grottoes, officials have struggled to develop steps to ensure visitors tour the caves quickly and leave.

“The aim is to get sightseers to promptly view the actual caverns and then closely look at the cloned ones,” said Wang XuDong, director of the Dunhuang Research Academy. "That way, both tourism and property preservation can go hand in hand."

Another issue at the Mogao Caves is that many structures were badly repaired in the past, drastically changing their original appearance.

The researchers will “super clone” the structures to reproduce their original appearance, using historical documents and other materials.

The technology has already been applied to the No. 57 cave, famous for its magnificent mural from the Tang Dynasty. The late Japanese painter Ikuo Hirayama called the mural the “beautiful Bodhisattva.”

Six Buddhist statues placed at a central stand in the cave do not appear to fit with the heritage site because of their sulky expressions, loud coloring and awkwardly shaped fingers.

“The statues do not match the mural because they were repaired by an amateur in the Qing Dynasty about 200 years ago,” said Li Lin, 55, an associate researcher at the Academy of Fine Art.

Working with Tokyo University of the Arts, Li in 2017 test-created two clay statues based on other Buddhist figures and other artifacts made in the Tang Dynasty.

He used a 3-D scanner to reproduce them on foam polystyrene using a robot.

Tang-style coloring was then applied to the polystyrene statues to recreate the original appearance of the Tang statues.

Masaaki Miyasako, 68, professor emeritus of art at Tokyo University of the Arts, lavished praise on the endeavor, saying, “Buddhist statues from the Tang Dynasty have been reproduced to match the mural from the same dynasty.”


According to Wang, about 250 grottoes have been scanned and digitized to date.

Under the project, Dunhuang Research Academy will learn from the Japanese university’s technique to copy the grottoes and statues. This will significantly cut cloning costs, after which the institute intends to use super clone technology to recreate how they originally appeared.