Dearn's Instant Fortress questions?

[RuminDange]

In our game a few things have come up in relation to the Instant Fortress. Such as:
1:How to enter a Dearn's Instant Fortress that the group's enemies are using to attack from since knock doesn't work? Can you teleport in, Ethereal Jaunt, etc.
2: What spells would damage the tower to make a hole that the party can get though. Such as will Slime Wave damage the tower?
Just figured I would seek everyone's idea's on this one, since I haven't seen any offical rulings on this and none in the description of the item. Except of course the tower is Adamantine with Hardness 20 and 100 HP (Which I guess it means the whole tower has 100HP)

RuminDange

 

[Quixon]

Well it doesn't say the Fortress has any special defenses(besides hard walls) so any of the normal tricks would work- Teleport ect...

And I have to ask- you do know the Fortress can't shrink back down once its been activated right?

 

[Pax]

And I have to ask- you do know the Fortress can't shrink back down once its been activated right?

Which, by the way, is an utterly ludicrous departure form previous editions, in which it COULD be shrunk back down and carreid away (made a nifty "wizard's tent" each night ... heh).

 

[Mahali]

Which, by the way, is an utterly ludicrous departure form previous editions, in which it COULD be shrunk back down and carreid away (made a nifty "wizard's tent" each night ... heh).

Since none of the earlier editions could shrink back down too it doesn't seem that ludicrous now does it?