No problem, the poison thing goes when you have conquered the Battle Tower. You can get back to the Broken Valley from the Sentinel Island via teleporters. Anyway, I think there is a teleporter in Maxos Temple...
Thanks scalla
Another problem a have! (I think)
Can I have the Battle Tower (and so on my Battle Chest!!) sooner that the point in the game "Brocken Valley is poisonous"??
I hope so, because this:
I know in the Battle Tower finally in can put things from my Inventory in a Battle Chest!! But if I have finally that Battle Chest ... and I can't back to Brocken Valley because of the poisonous gaz ... that's very sadly!!
Because I was planning to do: go back after put many things of my inventory in Battle Chest and than go for more loot in Brocken Valley 
... is this possible???
