This brings up a good question: Is it like the post Morrison (New X-Men) run where it was public knowledge that the X-Men operates out of Xavier Institute?"You assume that those legend were all truth. Maybe the Norse Pantheon was only supers. Assuming anyone owning the hammer can take advantage of it, we need to find how they could enter that place...
Would the X-Men could have done it. After all, I think they are establish not so far and I think they have someone who can move through wall and floor." suggest Gambit.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.