Sleeping Keyhole

A Sleeping Keyhole in Traverse Town.

The Sleeping Keyholes (眠りの鍵穴, Nemuri no Kagiana^?), also known as the Keyholes of Sleep, are seven unique Keyholes in the Sleeping Worlds. Like their counterparts in the Realm of Light, the Keyblade can interact with the Sleeping Keyholes by firing beams of light into them; however, that is where the similarity ends.

The location of a Sleeping Keyhole does not seem to be significant, as they often appear on nondescript walls, and Traverse Town's appears in the Fifth District, while its World Keyhole, the center of the world and its heart, is in the Second District. When a Sleeping Keyhole is unlocked, a large, almost circular section of the background behind it disappears with an effect reminiscent of shattering glass, revealing a torrent of gold energy and symbols underneath. This effect is also used when someone re-enters the Sleeping Worlds, as Sora does to thank the Spirits who helped him and Riku.

While the Heartless sought out the Keyholes of worlds to devour and plunge the world into darkness, the Dream Eaters seem unconcerned with the Sleeping Keyholes, instead focusing on attacking the worlds's inhabitants and generally causing mayhem. The known functions of the Sleeping Keyholes are to grant someone who unlocks all of them the power to awaken a sleeping heart, as well as freeing the Sleeping Worlds from their slumber. The Sleeping Keyholes may be indirectly related to the Princesses of Heart, as Yen Sid compares them when mentioning that as there are seven pure lights, there are seven Sleeping Keyholes.

By unlocking all seven Sleeping Keyholes, Sora and Riku obtained the power of waking.[?]

Sleeping Keyholes Location

Kingdom Hearts 3D: Dream Drop Distance

Destiny Islands: The Keyhole is located beneath the ocean, following the battle with Ursula. However, this is not one of the Keyholes of Sleep; it merely served as an entrance to the Sleeping Worlds and in Riku's case to Sora's dreams.
Traverse Town: The Keyhole is located in the Fifth District, after Joshua explains Young Xehanort is responsible for splitting the world into two different versions. A second Keyhole is located in the Third District after Spellican is sent fleeing to Sympohony of Sorcery.
La Cité des Cloches: On Sora's side, the Keyhole of Sleep is located inside the cathedral, in one of roof leveled windows. For Riku, it's in the central window of the cathedral at the Square.
The Grid: The Keyhole is located in the arena where Sora fights Rinzler and frees him from CLU's brainwashing. On Riku's side, it's at The Portal to leave The Grid.
Prankster's Paradise: For Sora, the Keyhole is located on a beach, after the battle with Chill Clawbster. For Riku's it's in Monstro's mouth, where Geppetto's boat is.
Country of the Musketeers: On Sora's side, the Keyhole is located in the courtyard. As for Riku, it's in the backstage of the Opera house, after the battle with the Holey Moley.
Symphony of Sorcery: The Keyhole for both of Sora and Riku is located in the Sorcerer's Loft in Yen Sid's room.
Dive to the Heart: The Keyhole is located on the platform after freeing Sora from Armored Ventus Nightmare, leading to the data Ansem the Wise placed in Sora. Another Keyhole is located within this data.