Cave 21 is the largest Tang dynasty cave with the exception of Cave 9. It now has traces of only a single larger than life-sized seated Buddha on the north (back) wall and five standing attendants (Photograph. Li 2003, color pl. 21). The cave is damaged by a large fissure in the stone that cuts across the east and west walls, thus the stone may not have been suitable for sculpting. It is possible that some of the figures formerly made for the cave were not attached to the walls, but carved separately and placed into the cave.