Mogao Caves, a UNESCO World Heritage Site filled with exquisite Buddhist art and manuscripts. Although the city had an early connection with Buddhism due to the passage of monks traveling the Silk Road, it was not until a monk had a vision of a thousand Buddhas above the desert at Dunhuang in 4th century that the famous caves were excavated and filled with the manuscripts and treasures. Nearby is the White Horse Pagoda, built by a monk from India in honor of his horse, which died in the process of bringing the monk to China. It is not possible to tour the caves on your own and all visitors are assigned to different guides (included in the ticket price). The tour takes about two hours and about 15 caves will be visited; all the rest are closed.