Introduction to Danbi Bridge: Danbi Bridge is the corridor that connects the south brick gate of the Altar of Prayer for Grain and its Nantian Gate (Chengzhen Gate). It is also the axis connecting the Altar of Prayer for Grain and the Circle Qiu Altar. It is 360 meters long and 30 meters wide. . There are three stone roads on the Danbi Bridge, the Shinto Road in the middle, the East Royal Road, and the West King's Road. They are high in the north and low in the south. The north end is 4 meters high and the south end is 1 meter high. Going north makes people climb up step by step, as if they are in heaven.