The White Stupa Monastery in Wuwei is the site of a Tibetan Buddhist temple of the Mongol Yuan period. In 1247, the Tibetan Sakya sent the Dharma-king Sakya Banzhida to Liangzhou to have talks with Koiten, son of Khan Ogedai of the Mongol Yuan government. The two parties reached a peaceful agreement on the affiliation of Tibet to China. In 1251, Sakya Banzhida passed away, and Koiten built for him a stupa in the White Stupa Monastery. So this temple constitutes a historical witness of the formal annexation of Tibet to the territory of China. The site is square in plan, measuring 420m from the north to the south and 400m from the west to the east. The stupa is in the southwestern corner of the monastery. Its base left over rammed-earth remains five meters high. In plan it is shaped like a cross with folded corners. The rammed-earth stupa core was built in the 13^th century, and surfacing bricks used in repairs of Ming-Qing times remain on its northern side. Excavation shows that beneath the stupa foundations is a square platform, which was built of rammed pure loess in the 13^th century, and the surface was plastered in lime. In the Ming period, the platform was enlarged and surfaced in brick. To the north of the stupa, a ruined building was revealed to be of the Qing period. In the center of the monastery, a little to the north, is the area of halls and pavilions.