Tongwancheng site is the site of the Daxia Guocheng City established by the South Hunnu nobles of the East Jin Dynasty. It is an earlier capital city in northern China. It is located in Baichengze Village, Hongdunjie Township, 58 kilometers north of Jingbian County, Yulin, Shaanxi Province. It is also called Helian City because it is built by Helian.