Zuoguocheng site is located in Nancun, Yukou Town, fangshan county. The ancient city of Tannan, Tanbei and Xihuangang were built, and the south of Dongcheng Tannan was built along the ridge line. Both inside and outside the surrounding cities. The inner city is rectangular, and the outer city surrounds the inner city with the change of terrain. The commanding city can be described as a solid and dangerous place. From the perspective of military geography and historical geography, it can be described as the first natural barrier north of Lishi.

According to documentary records and on-the-spot investigation, this city is the site of Gaolang Town in the Spring and Autumn Period, the Jade Pavilion of Nandan of Xiongnu in Gaolang County in Han Dynasty, and Zuoguo City, the capital of pre-Han Dynasty built by Liu Yuan. According to relevant data, the site has a history of at least 2500 years.

The remaining part of the northwest inner city of Zuoguocheng has been in ruins, and the foundation of the rammed earth wall in the southeast is basically well preserved. Some pre-Qin fragments, tiles, bronze vessels, etc. Rammed earth has also been unearthed in the city, which fully proves that the city was built in the Spring and Autumn Period and the Warring States Period.

So far, precious historical heritage has been preserved, which is of positive and far-reaching significance to the development of local tourism and the protection of cultural relics. On May 25, 2006, Zuoguocheng site was promoted from a provincial cultural protection unit to the sixth batch of key cultural relics protection units in China. The ruins of this ancient city have a history of more than 2500 years. The city was built in the Warring States Period, and Liu Yuan fought against Jin in the Sixteen Countries and the Han Dynasty, and built its capital here. The unique layout and unearthed precious cultural relics are well-known in the whole province, and it is one of the few minority capitals in China. Zuoguocheng in the Spring and Autumn Period and the Warring States Period was Gaolangyi, where Gao Luo lived, and Han was. In AD 140, Xihe County moved its capital to Lishi and built Zuoguocheng, where Nandan Imperial Court, the headquarters of the Southern Xiongnu, settled. It has become the core base of northern Xiongnu, Xianbei, Jieertie, Biandi, Qiang and other ethnic minorities. Brilliant for more than 400 years, it gave birth to a powerful "Lishihu" nation, which has a milestone significance in the history of national integration. Nandan Yuting did creative management here after she moved in. It was used and expanded in the Spring and Autumn Period, Warring States Period, Qin and Han Dynasties, backed by the eastern mountains and facing the Beichuan River. Built on the mountain, the city wall is surrounded by mountains on three sides, the east wall is built along the ridge line, and the inner and outer twin cities are closely guarded. The inner city is rectangular, and the outer city changes irregularly with the terrain. The whole building consists of three parts: the inner city, the west city and the east city, and becomes a military city defense that combines internal and external elements and takes care of each other. The outermost circumference is 9932 meters, with a total area of 8.7 square kilometers.