Of the various periods of cave construction at Yungang, the caves of the third period consist of small and medium-sized caves made according to a square plan that could be divided into various forms, such as three niches on each of three walls, double niches in the side walls, or multiple niches with multiple tiers on each of the three walls. As for the configuration of images within the niches, the most common layout was a horizontally organized series with careful attention to symmetry. Although the layout of both images and niche distribution varied, it can be seen that images combining the thought of the Saddharmapundarika Sutra with the Maitreya belief popular at the time of the second period of cave construction remained the main elements of composition
