Primary entry level of the Measureless Maze, via the stairs at top center. Secondary entrances are via the ladder at top left, and the stream at top right. Exits are top left (down a level), bottom left (down a level), bottom left (up a level), top/mid right (the room with the small pool; probably up a level, though it'd be a hard climb up a waterfall), bottom right (up a level), and bottom (access via the Shaft to several other levels).
Now that I look at this, actually, I'm going to close off a few corridors and add another set of stairs. I'll leave this version up, though.