Introduction to the Four Song Dynasty Steles: The Song Dynasty stone inscriptions "Pingjiang Map", "Astronomical Map", "Geographical Map" and "Emperor Shao Yun Map" are referred to as "Heaven, Earth, Man and City". The four Song steles were originally all It was placed in Dacheng Hall and is now moved to a wing on the side of the hall for special protection. It has extremely high historical and scientific value.