Floor plan taken from the game's own geometry. 674 floor sections, about 12.5k units across. North is up.
Every upward-facing surface of the map, projected straight down — ramps and sloped cave floors included, ceilings not. Numbered circles are doors and green diamonds are the ways out. Everything marked comes from the map's own event script. Stairs between levels and the secret walls a lever opens are not marked — neither is in the geometry.
Chest (7)Lever — opens a door (7)
Select a numbered door or a green exit on the plan, or in the lists below, to see what it is.