What kind of architectural structure is there in Badaling?

Badaling Guancheng is an irregular square with a door on the east and west sides. The East Gate engraved "Juyongguan Town" and the West Gate engraved "North Gate Lock Key". The base of the Great Wall on both sides of Guancheng is about 6.5 meters wide and the top is about 5.8 meters wide. The top of the wall is paved with three or four layers of city bricks, and the surface layer is square bricks. Outside the top of the wall is a brick crib with a height of only 2 meters. Each crib has an observation deck at the upper part and a shooting hole at the lower part, which can shoot the enemy. There are also drains and spouts on the wall. In the layout of the Great Wall, Badaling section still belongs to the Inner Great Wall. Standing on Badaling, you can see another imperial city and beacon tower site not far away, called "Wai", which belongs to the front line.