Grotto Key

The Grotto Key is a key found in Pirate's Grotto in Paper Mario: The Thousand-Year Door. It is found lying on top of barrels in the 2nd floor of the left storeroom in the north area (Ms. Mowz doesn't appear here.). The key unlocks the door on the right of the big stair room. The next room is a dark one with three Parabuzzies.

Mario must use Kooper or Admiral Bobbery to activate a switch in the storeroom while he heads for the wooden lift.