The threats are complex. But these laboratories are state of the art. Experts can analyze every single component of the paint, simulate conditions inside the caves, and identify all substances retrieved from the relics. This helps them keep authenticity in their restorations.

And there’s another, enormous project underway. Mogao is going digital.

So the basic idea of the Digital Dunhuang Project is to use new technologies to protect cultural relics. It aims to build a database containing detailed digital information and high quality color images of the treasures.

Inch by inch, these experts have taken six thousand photos in this one cave over the past month. Together they form a full record the grotto.

Yu Shengji, photographer of Digital Center of Dunhuang Academy, said, "The Mogao caves are fairly complex in shape. They all vary. So the shelves must be reassembled every time, and the shooting distance must be measured and calculated accordingly."

Once photographs are taken, they’re put together. And this is only the preliminary check.

Ding Xiaohong, Image Specialist of Digital Center of Dunhuang Academy, said, "We check if the exposure and focus are OK. And we also make sure of the quantity. We can’t miss anything. And then we adjust the colors."