Daern's Instant Fortress (Magic Cube)

This metal cube is small, but when activated it grows to form a tower 20 feet square and 30 feet high, with arrow slits on all sides and a machicolated battlement atop it. The metal walls extend 10 feet into the ground. The fortress has a small door which will open only at the command of the owner of the fortress—even knock spells can't open the door.
The adamantite walls of Daern's instant fortress are unaffected by normal weapons other than catapults. The tower can absorb 200 points of damage before collapsing. Damage sustained is cumulative, and the fortress cannot be repaired (although a wish will restore 10 points of damage sustained).
The fortress springs up in just one round, with the door facing the device's owner. The door will open and close instantly at his command. People and creatures (except the owner) must be careful not to be caught by the fortress's sudden growth. Anyone so caught sustains 10d10 points of damage.
In a Dragonlance campaign: Daern's instant fortress does not exist on Ansalon. 
Category:DMG Magic Items
Category:Encyclopedia Magica Magic Items
Category:Magic Items
Category:Magic Cubes