It can be found in the Hall of the Cornerstone, a hidden room under Mickey Mouse's throne and accessible only by pressing a hidden switch under the arm of the throne. Although it is a powerful artifact and heavily protected, Maleficent takes advantage of a door that appears into Disney Castle-exile Pete's past after he is made miserable by her constant abuse. Using the door, Pete is sent back in time to when the castle had yet to be built, and the Cornerstone sat unprotected on a hill.