It was called "Wanghaimen (Building)" in the Five Dynasties and "Guofengmen (Building)" in the Song Dynasty. The Yuan Dynasty ordered the whole country to tear down the city and destroy it, so Haishu Building at the south gate of Zicheng was doomed. In the first year of Yuan Dynasty (A.D. 132 1), another city with a first floor was built, named "Mingyuan Building", which was soon destroyed. In the ninth year of Xuande in the Ming Dynasty (A.D. 1434), Huang Yongding, the satrap, was rebuilt. In the 13th year of Wanli in the Ming Dynasty (AD 1585), Cai Guiyi, the satrap, was about to fall, so the renovation was renamed "Haishu Building", with Shen as the inscription and Dong Weifu as the inscription. In the 5th year of Emperor Kangxi (A.D. 1666) of Qing Dynasty, it was rebuilt many times after that. In the 47th year of reconstruction (A.D. 65466), the existing buildings were rebuilt in the 5th year of Xianfeng (A.D. 1855). Haishu Building, also known as "Bridge Building", is commonly known as "Drum Tower". It's engraved with leaks and drums telling time.