For example, the "large" city gate tower is 95 meters long and 10 meters thick. Entry roads into the city were more than 30 meters wide and linked to a network of urban traffic. Fortified barbicans can be seen on both gate ruins.

Outside the western wall of the palace city, there is a north-south road with a three-layered surface. The two lower layers are paved with large stones and small, densely packed pebbles. Wheel ruts are still visible. Along the edge of the wall, archaeologists have also found pottery drainage pipes.

"The findings not only advance our understanding of the form and nature of the Zhouyuan settlement, but also provide indispensable research material for the history of urban development in China," Chong says.

Zhao Hui, a professor at Peking University, comments: "The greater significance lies in the fact that the site provides a framework that enables us to better understand past discoveries. These cities mark a new era in the field archaeology of Zhouyuan."