The fate of the Empty Crown after the events of the Exomorph crisis are unknown; they may have been decimated or their organization may still exist within the Romulan Star Empire. However, Kleeya has revealed rumours to the attention of starfleet that a master key has been built, allowing control of exomorphs without the need for a control facility.
Screenshot from level city4, the Bar
Idk this looks rather blocky the walls uncreative flat.
Keep working on it improve the walls a little. Either by some support pillars or maybe some rounded up sections just to make it look nicer. It doesn't always have to be structural accurate.