The Great Wall of Shuiguan is located in Yanqing, the eastern part of the Badaling Great Wall. This Great Wall is built in the mouth of the dangerous valley. The Great Wall of Shuimen Arrow Building is a "V" type, which follows the mountain. If a dragon is like a dragon, it wants to fly. The Arrow Building is the enemy building and has the effect of water gate. This kind of construction method is extremely rare in the Great Wall along the route, so it is called the Watergate Great Wall.