The Mirror Bed

The whole floor is one tank of water, so still that the vault overhead is laid out in it a second time, every brick and every crack, and your light burns in both. Nothing has disturbed it in living memory. Nothing should. The walls stand 8 paces apart one way and 5 paces the other: a great open hall. The roof is held up on rows of pillars, thick as a barrel and plain as a post.

Depth 50.

First found by Wanderer #1.

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