Castle Oblivion

Castle Oblivion is the setting of Kingdom Hearts: Chain of Memories, and the only world the characters actually visit. It is controlled by Marluxia of Organization XIII. There are thirteen above ground floors, and 12 basements.

In Chain of Memories
Sora, Donald, and Goofy follow Pluto into Castle Oblivion. As soon as they enter, they forget all their skills, and are forced to use the castle's card-based combat system. The higher they progress up the Castle, the more memories are reshaped by Namine. This is so that Marluxia and Larxene can use Sora as a puppet to overthrow Xemnas. The scheme fails thanks to Axel, and Marluxia and Larxene are killed.

Reverse/Rebirth Mode
Riku awakens inside the lowest basement of Castle Oblivion, as a result of his connection to Sora. Here he faces his memories of both Xehanort's Heartless and Maleficent, and overcoming his fear of the darkness within himself. It was within the Castle that he meets DiZ and Namine, as well as reuniting with King Mickey.

Residents

 * Marluxia - Deceased, killed by Sora.
 * Larxene - Deceased, killed by Sora, Donald and Goofy.
 * Axel
 * Vexen - Deceased, struck down by Axel.
 * Lexaeus - Deceased, killed by a possessed Riku.
 * Zexion - Deceased, killed by the Riku Replica.
 * Namine