Mogao Caves, Dunhuang, Gansu Province, China

On the edge of the Gobi Desert there are about 700 man made caves that have been dug into the hill side, about 400 of them painted inside, like this one on the left, with Buddhist altars within. 
These are truly amazing to see.  Photos do not capture their beauty.
We were only able to go into 14 of them, but they are larger than life and awe inspiring.  From the 4th to the 14th century, hundreds of caves were painstakingly hand carved out of the alluvial conglomerate rock cliff face, under the sponsorship of Buddhist monks, local officials, and wealthy families who wished to build karmic merit and perform an act of veneration. Although a Buddhist site, the art and objects found at Mogao reflect the meeting of cultures along the Silk Road, the collection of trade routes that for centuries linked China, Central Asia, and Europe. Discovered at the site were Confucian, Daoist, and Christian texts, and documents in multiple languages including Chinese, Sanskrit, Tibetan, and Old Turkish. Even Hebrew manuscripts were found there.
 The Library Cave (Cave 17), which was unsealed by Wang Yuanlu, contained nearly 50,000 ancient manuscripts, silk banners and paintings, fine silk embroideries and other rare textiles dating from before the early 1000s, when this cave and all its contents were concealed for reasons still unknown. The Diamond Sutra, the earliest and complete printed book with an attested date (868), is among the most notable documents found in the Library Cave. Using carved wooden blocks, the book was printed onto strips of paper that were then pasted together to form a scroll.