The Flooded Cistern

Green growth follows the mortar lines, thriving on no light at all. The space opens out into a small chamber, roughly 2 by 1 paces. A cairn of loose stones stands against one wall, deliberately made. A depth is marked on the wall in wax pencil, struck through, and marked again lower. Something small goes quiet when you enter, and stays quiet.

Depth 5.

You are reading the dungeon, not walking it. Rooms are only created by people, and only from inside the maze.