Hall of the Cornerstone

The Hall of the Cornerstone is a place in Disney Castle, and the holding place of the sacred Cornerstone of Light. It is located below ground, and the entrance lies before King Mickey's throne. It also holds the door to the world Timeless River.

Trivia

 * In Kingdom Hearts II, when Maleficent begins to take Disney Castle with her dark magic, the hall is covered in thick, black thorns, similar to the ones surrounding Maleficent's castle in Sleeping Beauty.