The Old Castle is a medieval-styled castle that is the lair of Evil and the final stage in the videogame Densetsu no Starfy 3. Starfy fights Ogura there. To battle Evil, the hero Starry must face Ogura again after beating him once.
During the story, there was a search to find this location, called the "Old Castle Search Team" (Japanese: こじょうたんさくたい) and Kyorozou told a Pufftop Guard he wanted to become part of the team in Sea of Sky's Area 1. It is implied that he was made a member.
- It shares the same name with another castle from Digimon Frontier.