I'm just been in the Mages Guild in Ald'Ruhn. There is a locked and trapped door. Behind which is a lava wall with "A Magicky Portal Thing To An Outer Plane Of Existence".
WTF?!
If I go through it I end up somewhere called Cratehall guarded by to guys with crates on their heads.
It looks like screenshots look like for the Steampunk add-on - "Deus Ex Machina" - except the walkthrough makes no mention of it and I cannot find any references to cratehall.

It's cool and all but does anyone know what it is about?
I have screenshots!!

Can we see them? sounds like some bizarre mod side effect.

Actually, further investigation leads me to believe I unknowingly blundered into part of the Deus Ex Machina mod! But I was like "WTF?!11/1?!!"