> Trying to find it the way that you said was impossible because some squares had extra doors in them and some doors did not go in the direction that you said.

I wasn't giving you step-by-step directions (and don't feel right giving you coordinates). I just meant to work your way to the north at first, until you get to the northwest corner of the block of walls -- but in doing so, you'll be moving back and forth a lot. It's a twisty path.

Just work your way north to the northwest corner of the block of walls, then work your way generally to the east, then work your way generally north again. You should find it, but if not, an exhaustive methodical search will also get you there. There's absolutely no trick to this level; it's just a matter of exploring the level completely.