Introduction to the coupon top door openings: There are 5-meter wide coupon top door openings on all sides of the platform base, leading to a cross in the middle, connecting Jiefang East and West Streets and Gulou North and South Streets. There are stone inscriptions on the forehead of the four sides of the cave, which are "Ying En" in the east, "Lai Xun" in the south, "Yu Shuang" in the west, and "Gong Ji" in the north. There is a gate on each side of the east door opening. The south gate is inscribed "Kun He" on the forehead, and there is an ear room inside; the north gate is inscribed "Qianpi" on the forehead.