This Chaos City was the chaos defense system built back in the day by the ancestor of the Shangguan clan, the legendary Great Emperor Shangguan Zhaixing.
Shangguan Zhaixing's two major contributions back then were, first, the construction of the Upper Realm Heavenly Palace, which instantly connected all powerful families possessing imperial clan inheritances to Central China.
These great families were stationed in the void, a million miles above Central China.
Chapter 190