Daern's Instant Fortress
With a touch, you transform this iron cube into a fortress that protects yourself and your friends.
Wondrous Item 325,000 gp
Utility Power Daily (Standard Action)
Effect: You create a square adamantine tower that occupies a close blast 5. You must create the tower in unoccupied squares. Its walls are 30 feet high, extend 10 feet into the ground, and are impervious to damage. The top 5 feet of the tower is a sealed battlement, and it has windows on all sides that allow a view of the nearby terrain, but which cannot be attacked through in either direction. It has a small door that faces you when the tower is created, and which opens only to your command or a DC 36 Strength check. The door provides the only access to the tower.
The tower provides a safe location for you and your allies. It includes sleeping and living quarters for up to twenty Medium creatures, though it has no sources of food or water. The tower lasts until you dismiss it from the outside as a standard action, returning it to its cube form. Creatures within the tower when you dismiss it are teleported to squares in or adjacent to the tower’s area.
Published in Mordenkainen's Magnificent Emporium, page(s) 82.