Mingdu in the Sun Moon Empire indeed has no city walls; Jing Hongchen had once proudly explained this to Huo Yuhao.
However, this did not change the reality that the Sun Moon Empire was effectively divided into three distinct zones: the Inner City, the Outer City, and the Imperial City.
Each zone was sharply demarcated, and what Huo Yuhao was about to do was to turn these three cities, once separated merely by convention, into cities partitioned by solid stone walls.
Chapter 1255