Introduction to watchtowers: Watchtowers are densely packed on the Jinshanling Great Wall, usually 50-100 meters each. The wall is based on boulders, 5-8 meters high, and is equipped with blocking walls, stacked walls and barrier walls. , various forms, each with its own characteristics. The watchtowers include brick-wood structures, masonry structures, single-story buildings, and double-story buildings. There are not only flat roofs, but also dome roofs, boat roofs, and four-corner and octagonal spires. It can be said that there is one style on each floor, each with its own characteristics.