The Room Destroyer (Trap idea)
Here's one for you DM's that want a powerful trap (Note please have an alternate route planed for the party if this item is planned to be used) The players have enter a long room, & as they walk acrossed it, they step on some sort of pressure plate in the middle of the room. A bit after that & they start to hear rumbling. Soon enough a giant drill falls from the celling & lands at the begin of the hallway. The drill will begin to quickly make it's way to the other end of the room. If a player get's caught in it they will take 2d12 damage. Once the drill makes it to the end of the hall it will stop & the room will collapse in on itself.