
This mural is located on the back (west) wall. According to the Mahaparinirvana Sutra, after the Buddha entered parinirvana, the kings from eight kingdoms fought for the Buddha’s relics before it was decided that the relics would be divided among them. Each kingdom built stupas to enshrine the relics.
The type of stupa illustrated in this painting is called the Diamond Throne Stupa, with four smaller stupas standing at each corner of the large stupa in the center. The special features of the stupa include a broad base and gilded finial. On the lowest tier of the large stupa are four warriors supporting the upper tiers. The middle tier illustrates the birth of Prince Siddhartha, and the upper tier portrays his enlightenment. The base of the spire is shaped like an inverted bowl with a golden garuda in the center. The finial consists of seven stacked rings surmounted by an crescent moon, a canopy, and jewels. Long, narrow banners hang from the canopy. The sides of the stupa are protected by the Four Heavenly Kings, above which are flying apsaras.
For more details, go to the Encyclopedia of Buddhist Arts: Caves Mo-S, page 1213.