The Great Wall was originally built in the Spring, Autumn, and Warring States Periods as a defensive fortification by the three states: Yan, Zhao and Qin. 

At that time, Yan, Zhao, and Qin states were often harassed by the powerful northern nomadic tribes, and they built walls and stationed troops on garrisons along their northern borders. Construction of the series of Great Walls thus began. 

After Qinshihuang unified China, he demolished the walls between the various states, leaving behind only those of Yan, Zhao and Qin and linked them together, so as to resist the attack by northern nomadic people.

A section of the wall stretches one hundred kilometers in the territory of Baotou, and the wall in Guyang County, 10 meters high, present a magnificent sight. The Great wall of Zhao State, situated in Shiguai district, is the oldest part of the Great Wall existing today.