Lie City Introduction: is called "Horse Circle" and "Parade City" by the locals. It is located on the commanding heights on the east side of Shuiguan. It is easy to defend but difficult to conquer, but it is elusive and out of reach. It covers an area of ​​about 3,000 square meters. On the one hand, it is used to confuse the enemy, and on the other hand, it can centrally store grain, horses, soldiers, etc. It is an original creation in the Baiyangyu Great Wall defense system.