The Mogao Grottoes are located about 20 kilometers southeast of the city of Dunhuang. There are some 490 grottoes over a stretch of 1,600 meters on the cliffs there. The construction began in the early 5th century during the Northern Liang Dynasty period and continued into the Yuan Dynasty era. The site houses a total of 2,415 statutes and the area covered by murals extends over 45,000 square meters. Among the numerous grottoes, the Zangjing(dong) cave found in 1900 is of particular importance. The Buddhist art in the Mogao Grottoes as well as the Dunhuang documents is ranked among the most significance historical material in China.