Chinese researchers are taking digital inventory of a collection of ancient sculptures and artwork at the Maijishan Grottoes in northwest China's Gansu province, local relics protection authorities said.

The Maijishan Grottoes, translated as Wheat Stack Hill, is a 1,500-year-old UNESCO World Heritage site home to 10,632 Buddhist sculptures.

Sun Xiaofeng, researcher with the Art Institute of Maijishan Grottoes, said preparation for the digital archive began in 2010, when they attempted to list the grottoes as a UNESCO World Heritage site.

"The work has proceeded slowly as images are hard to collect from the sculptures, most of which are located in narrow spaces on the cave walls," said Sun. Digital mapping work has been completed at 50 caves by far, and 170 others remain to be finished.

The institute has selected Wuhan Huayu Century Technological Company, which has experience creating 3D images of the frescos at the Mogao Caves in Dunhuang, also in Gansu, to work on the project.

High-resolution photos will be taken and entered into the digital archive, said Huang Liping, general manager of the company, adding that the 3D images will show pictures of sculptures that are as true as possible to the originals in shape, texture and color.

Some of the caves, which are severely damaged by natural erosion, will be closed to the public after the archive is created.

"Tourists will see the digital images instead," said Sun.

Maijishan is home to 221 grottoes. It was added to UNESCO's World Heritage List in 2014 along with other sites along the Silk Road, a route that linked China with the rest of Eurasia through trade and cultural exchange.