Introduction to the Stone City that enters the sea: The Stone City that enters the sea is the end part of the old Longtou Great Wall extending into the sea. Standing in the sea and connected to Jinglutai in the north, it forms a commanding height that blocks the sea. The stone city entering the sea is 22.4 meters long, 8.3 meters wide and 9.2 meters high. According to historical records, it was built in the seventh year of Wanli in the Ming Dynasty (1579) by Qi Jiguang, the commander-in-chief of Jizhen, and Wu Weizhong, the general of the line.