Kaiyangbao is located in Kaiyang Village, 20 kilometers southeast of Yangyuan County, Zhangjiakou City, Hebei Province. In ancient times, it was a frontier fortress leading to the Central Plains south of Yanmenguan, and it was also a battleground for military strategists. According to "Atlas of Chinese History", Kaiyangbao was Anyang, the county of Zhao in the Warring States Period. This is the most primitive and desolate castle. The walls of the castle are rammed with chalk and yellow mud, which is a local specialty. Today, although the walls of the castle have experienced thousands of years of wind and rain, they still retain the original outline.
Introduction:
The whole castle is now planned on the back of a turtle shaped like a water turtle. The streets in the castle are built according to the principle of "Nine Palaces and Eight Diagrams". Now the city walls, gates and streets are basically well preserved, but the buildings are incomplete. Only from the smooth stone strips laid on the inner surface of the city gate cave and the two ruts that have been crushed by people, we can vaguely see the prosperous traffic and merchants in those years.