I wonder this :
maybe "the entrance" to this dungeon is one of the "secrets" to find, and let it just be that this entrance is a very very good hidden secret ?!
I'm planning to play D:OS very thoroughly, searching every inch, move everything that's not nailed to the ground ... maybe I can find this dungeon for you ? Who knows ?
But then you've have to be very very patient !
I've not much time to play ... and knowing my play style is "thoroughly" ....
