The imperial city in Wildlands.
It is the main city of the Arch Emperor dynasty.
Originally, the city had 9 layers, but 6 layers were destroyed in the battle between Daoist Heavenspan and the Arch Emperor dynasty. Then the city moved itself to the Wildlands.
In the wildlands, only the top 2 remaining floors are visible, the third floor is underground.
It is actually a world treasure.