To save the art in China’s Dunhuang caves from mobs of tourists, conservators are scanning the caves ad creating digital images. “Officials will scan 45,000 square meters (54,000 square yards) of frescoes, or about the area of 10 football fields, and 3,390 Buddhist statues. The images will form a virtual-reality tour for visitors to see before they enter the grottoes. The project, a collaboration with the Mellon Institute in Pittsburgh, may take five years to record the first 20 of 492 caves.”