Tunhwang (both: do͞on-hwäng), town, extreme NW Gansu prov., China. Crescent Lake, a noted tourist attraction surrounded by high sand dunes, is there. The Caves of the Thousand Buddhas (Mogao Caves) are at nearby Qianfodong. The town and its environs were long a gateway between central Asia and China, and the frescoes in the caves, painted from the 5th cent. to the 13th cent., show Indian, Greco-Roman, and Iranian influences. Closed for centuries, the caves were reopened in 1900. There, Sir Aurel Stein, an English archaeologist, discovered a library of some 15,000 manuscripts, including the Diamond Sutra, reputed to be the first (A.D. 868) printed book. China reclaimed the caves in the 1940s and in 1979 they were opened to the public. By the 2000s, however, the paintings were threatened by human-generated damage, and now only a few of the hundreds of caves are open to tourists.