Introduction to Chenghai Tower: Chenghai Tower is located on a large platform in the middle of the city platform 20 meters north of Nanhaikou Pass. The building is 14 meters high and has two floors. It faces south and is the absolute commanding height of Laolongtou. Chenghai Tower was built in the Ming Dynasty and rebuilt during the Kangxi and Qianlong years of the Qing Dynasty. Upstairs, there are plaques written by Sun Chengzong, a great scholar of the Ming Dynasty, "Xiong Shiwanli" and "Chenghai Tower" written by Emperor Qianlong of the Qing Dynasty. The walls of the building are inlaid with several lying tablets written by famous historical figures, and cultural relics unearthed near Laolongtou are displayed in the building. Standing upstairs, you can see the vast sea to the south and the Xiongguan Road and the beacon towers to the north.