AHHHHH, I'm dumb I figured you had already gone to the side rooms and such. Yeah to the south of the ruins is the omni sanctum which is surrounded by side rooms, three on each side, the first time you enter them an event fires, telling you to speak with Zessura about upgrading the side rooms. Have you not entered the side rooms yet? (The north of the ruins leads nowhere, it's to the south)
Funny you should say that, all of my newer maps make use of stairs or pathways that end in darkness to indicate doorways.
The ruins were one of my first maps and I was still getting used to map creation. I originally planned to use stairs to indicate the lower levels in the pool chamber as well, but the game engine doesn't have sideway facing stairs.
Newer maps focus on using a top down approach usually because of this.
I've edited the ruins and pool chamber to better reflect these pathways.