The Gansa corridor("west of the river") that connects Xi'an and Dunhuang is a land belt surrounded by mountain ranges and deserts and because it stretches to the west of the Yellow River, it is called the Gansu corridor.
Binglin Grottoes is 17 kilometers west of Yongjing in Gansu province where the Yellow River is dammed and is one of the three great grottoes in the Gansu province of China along with the Mogao Caves in Dunhuang and the Maijishan Grottoes in Tianshui.
"Bingling" means "Hundred Thousand Buddhas" in Tibetan and as the name indicates Bingling Grottoes has stone caves enshrining tens of thousands of Buddhas. Construction of the caves began either in the latter part of the 4th century or early 5th century and over a period of 300 years many caves were constructed and decorated with stone statues, clay figures and mural paintings. 183 caves remain today. A 27 meter Great Maitreya Buddha stands carved on the cliff-side near the river. The Buddha from the waist up is carved into the rock and the bottom half is constructed of a mud mixture. One can see damage from erosion. The 169th cave is the oldest of the caves found at Bingling Grottoes and is 6 meters high with 32 square meters of floor space. The cave is decorated with paintings of flying celestials and a teaching Buddha, stone statues with peaceful expressions on their faces, and clay figures. The inscription in ink on the wall of the cave reads the first year of Jianhong in Western Qin (the year 420).