This cave was excavated in the early Tang Dynasty. The Buddha statue in this cave is 35.5m high with a width of 12m between knees. It is the largest Buddha statue at Mogao Grottoes.

According to Dunhuang manuscript Record of Mogao Grottoes, the giant Buddha was built in 695 under patronage of a Buddhist master Lingyin and a lay Buddhist Yinzu. The giant Buddha was cut from the sand-stone and then clayed outside, and at last painted. The statue has lost its original appearance due to restorations, yet its grandeur is still kept.

The building in the front of this cave is nine-storied tower, as the name thus came. The Nine-storied Tower originally had only four stories, one more story was added to it during the Late Tang period (874-879). It underwent a restoration in the early Song Dyansty (966). The present Nine-storied Tower was built in 1935 and has become a representative of the Mogao Grottoes.

Sine the Late Tang Dynasty, a square (or horse hoof shaped) altar is very often excavated at the center of the main hall of a large-sized cave, and behind the altar is a back screen connecting the ceiling of the cave. There are steps in the front of the altar, a group of colored stucco statues are placed on the altar, the Buddhist believers can walk around the altar to worship the Buddhist statues and show their homage. This type of cave is one of the main hall styles and is similar to the form of temples or even the secular palace.

Also known as the Wenshu (Manjusri) Hall. It was constructed during the period from 947 to 951 of the Five Dynasties under the patronage of local governor Cao Yuanzhong. The ceiling of this cave is of an inverted-dipper type with a shallow shrine at each of its four corners painted with four heavenly kings, which is a characteristic of the caves excavated during the Five Dynasties. The east wall and the lower eastern sides of the south and north walls are painted with portraits of Uighur princess, Khotan princess, female donors of the Cao family. In the center of the main hall is a horse-hoof shaped altar with a rear screen. The most representative wall painting of this cave is the Mountain Wutai Map in a large canvas at the west wall, which is 13m long and 3.6m wide. It is the largest painting of landscape and human figures among the Dunhuang wall paintings, and the largest panoramic historical map, depicting in detail the landforms and social activities ranging from Zhengding, Hebei Province in the east to Taiyuan, Shanxi Province in the west. Some 170 odd towns, temples, towers, pavilions, Buddhist pagodas, thatch cottages, and bridges painted in this map provide precious historical material of ancient architecture.

This cave, also known as the Hidden Library Cave, is located at the north wall of the corridor of cave 16. It was excavated during the Late Tang Dynasty in the honor of Hongbian who was Buddhist governor of the Hexi Corridor. At the beginning of the 11th century, a great abundance of Buddhist scriptures, paintings, instruments, and other religious and social documents, as many as some 50,000 pieces in total, were secretly stored here, then the door of Cave 17 was sealed with a new wall with paintings. As time passed by, the closure of this cave gradually escaped people`s memory......

It was till 1900 that this sealed cave was accidentally rediscovered by the Taoist Wang Yuanlu when he was removing sand accumulated there. Yet to our great sorrow, during the period from 1905 to 1915, the British Aurel Stein, Frenchman Paul Pelliot, Japanese Kozui Otani, and Russian Oldenberg successively arrived at Mogao and tricked away from Taoist Wang nearly 40,000 pieces of the precious ancient documentations at a throw-away price.

The all-inclusive documentations from the Hidden Library Cave cover such fields as politics, economy, military affairs, literature, history, geography, medicine, science and technology, folks, religions, and art etc. from the fourth to the eleventh century. Besides Chinese-language manuscripts, there are quite a few documentations in Tibetan, Uighur, Khotanese, Sogdian, Turki, Rabbinic, Sanskrit etc. The abundant precious historical documentations draw attentions from scholars in China, Britain, France, Russia, America, and Japan, whose research contributes to emergence of an internationally known new subject, i.e., the Dunhuang Studies.