Introduction to Wumadu Square: It is said that at the end of the Western Jin Dynasty, the world was in chaos. Five princes of the Sima clan fled from the north of the Yangtze River and crossed the river here. Among them, Sima Rui, the king of Langya, rode the wind and turned into a dragon and flew here, becoming the emperor. A good omen before the establishment of the Eastern Jin Dynasty in Nanjing.