The Castle of Dreams is a Bonus Dungeon located on the East Elencia continent in Grandia. A cursed dark place hidden in the south Zil Desert and inhabited by two twin sisters mourning the death of their father.
At some point in the past, one of the sisters became possessed by the Lightning Sword and slayed the Lord thus transforming the castle into the chaotic place and enraging the spirit of their father.
As the Castle of Dreams is an optional dungeon, there are no specific story points. The quest in this dungeon is to defeat the Lord's Ghost and retrieve the cursed sword that haunts the castle. Many monsters now inhabit the castle and must be defeated in order to gain access to the Lord's chamber which is in the highest peak of the castle.
- Despite being an optional dungeon, the Castle of Dreams has more battle backgrounds than any other area in Grandia, with a total of 7.