Kaiyangpu(开阳堡), according to **[SHI JI](https://en.wikipedia.org/wiki/Records_of_the_Grand_Historian)**, the most important history book of China, the name of this city fortress can be dated back to 300 BCE, historian believe the formation of the city and some building are from Tang dynasty(618–907).
There is only one entrance to the south, all the wall was built of rammed earth, the size of this fortress is 300m x 215m.
This is a big model so please be patient, it will take some time to load.
To see the detailed city gate please click [**here**](https://skfb.ly/StMS).