The Surveyors' Room

A table was bolted to the floor here and then taken away, leaving four bright squares in the dust and the bolts still standing proud. Whoever worked at it worked carefully: there is a plumb-line hook set exactly at the room's centre, and a level scratched along the north wall that is still, after everything, level.

Depth 3

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