Castle of Dreams

Castle of Dreams is a world that is featured in Kingdom Hearts Birth by Sleep. It is based on the 1950 Disney film, Cinderella. It is the first world that Aqua visits.

Kingdom Hearts Birth by Sleep
Ventus was the first to visit this world. As he arrives, he is shrunk to the size of a mouse and finds himself in a mouse trap, taking over the role for Gus, Jaq's best friend. He is rescued by Jaq and Cinderella, who is the servant to her stepmother and two stepsisters (Anastasia and Drizella). As Cinderella is called off to help them, Jaq tells Ven that a ball is being held at the king's castle, and Cinderella can only go if she can find a dress. To help her get there, Jaq and Ven decide to find the last of the materials for the dress. Ven travels down through the house to find them and brings them back to Jaq. The last item on the list is a pearl, which is guarded by the Tremaine's evil cat, Lucifer.

Ven sneaks up on the sleeping cat, but Lucifer awakes and attacks. Jaq fends him off with a ball of yarn and gets away with the pearl, while Ven stays and fights. Lucifer is defeated and runs off. When Ven returns, he asks Cinderella if she is looking forward to the ball. Not knowing her dress is finished, she tries to cheer herself up by saying that ball would be boring anyway. But then Jaq reveals the dress and Cinderella is excited that her dream can come true. She goes off to the ball, and Jaq asks Ven what his dream is. Ven answers that it is to become a Keyblade master with his friends.

Terra arrives in the Tremaine's garden and meets a crying Cinderella, whose dress was torn to shreds by her evil stepsisters. Terra senses the light in her heart and tries to get her to believe in that strength, but her negative feelings at the ruin of her dress and dream bring out the Unversed. Terra defeats them as the Fairy Godmother appears. She uses her magic to create a carriage, a dress, and glass slippers for Cinderella, but warns that the spell will be undone at midnight.

Cinderella goes off to the ball, and Terra asks the Fairy Godmother why she fulfilled Cinderella's dream for her. The Godmother replies that believing in one's dreams is work enough to deserve them and says that he should see for himself. Terra goes to the castle and escorts Cinderella through the halls of Unversed to the ballroom.

Cinderella meets Prince Charming and dances the whole night with him. Terra meanwhile senses an Unversed, and fights a giant one, the Symphony Master, disrupting the ball. He defeats it as the clock strikes twelve. Cinderella runs away before the spell is undone but does not tell Charming her name. As she runs down the stairwell, one of her glass slippers falls off and is picked up by the Grand Duke.

Terra leaves as well and meets Aqua at the entrance to the castle. She asks what he has been up to after hearing of the dark deeds he committed in other worlds. He tells her that Master Xehanort is looking for the Princesses of Light, but is not in this world. Aqua still wants to look around and heads in the ballroom as Terra leaves.

After her meeting with Terra, Aqua heads into the ballroom and finds out that someone left her glass slipper behind, in the process sensing a notably strong darkness within Lady Tremaine's heart, concerning her greatly. Prince Charming and the Grand Duke decide to tour the kingdom to find the girl whose foot fits the slipper. Aqua follows them to the Tremaine's manor, with the intention of killing Lady Tremaine before her darkness harms anyone, but meets the Fairy Godmother, who advises her not to do it, since Light and Darkness must co-exist, something Aqua had not learned from Master Eraqus. The Fairy Godmother tells Aqua that Cinderella has been locked in her room by Lady Tremaine, so that she cannot meet the prince. The Fairy Godmother shrinks Aqua to then size of a mouse to help her rescue Cinderella without being seen by Lady Tremaine. Aqua meets Jaq inside and protects him from the Unversed as he carries the key to unlock Cinderella's door. Once she is rescued, Cinderella heads downstairs to try on the slipper.

Aqua looks on from the banister, but suddenly grows and grows to normal size and falls to the floor. She is able to distract the Grand Duke long enough for Cinderella to come down. Tremaine breaks the slipper to keep Cinderella her servant, but Cinderella pulls out the other one. She goes off to meet the prince to the castle, but Aqua hears a scream shortly thereafter. Tremaine and the stepsisters had summoned a giant Unversed, a Cursed Coach. They laugh as it attacks Cinderella, but before Aqua can strike Tremaine, a fire bomb from the Unversed lands on Tremaine and her daughters, blowing them away.

Aqua faces the Unversed and defeats it and sees the reunion of Cinderella and Prince Charming. Aqua, however is still worried about Terra's darkness, but the Fairy Godmother informs her that Terra had helped Cinderella's dream come true, renewing Aqua's hope.

During the credits, a scene is shown of Cinderella dancing with Prince Charming as Jaq and the Fairy Godmother watch from the balcony.

A fragmentary passage
Sometime after Aqua falls into the Realm of Darkness, she comes across the castle jetting out of a sea of darkness. She watches in horror as she sees the world being swallowed by darkness.

Trivia

 * Castle of Dreams is very similar to Wonderland in the sense that Ventus and Aqua are able to shrink size, and that there are secret entrances to other areas. While Aqua is shown to be shrunk by the Fairy Godmother, it remains unknown as to how Ventus was shrunk, as he himself wonders aloud how it happened.
 * In early trailers, Ventus is shown looking at the Castle Entrance with awe as Cinderella approaches, but in the actual game, this scene never occurs.