Forge v36.2.2
Minecraft v1.16.5
Lost Cities v4.0.10-beta

I've noticed that if cities generate near water, it forms these underwater borders around the city. It happens every time from what I've seen.

Seeing similar
lostcities-1.16-4.0.11-beta.jar
forge-1.16.5-36.2.2

8

I'm also noticing this behavior(can add screenshot if needed)

lostcities-1.16-4.0.12-beta.jar
forge-1.16.5-36.2.34