in the Pokemon videogame
s and cartoon
It is the home of Misty's gym, where you will battle her water-based Pokemon.
Important game elements:
Cerulean is also contains the entrance to the Unknown Dungeon, which is the final place in the game you are allowed to explore. Mewtwo can be captured there after you win the game by defeating the Elite Four.
In the time period of Pokemon Gold, Silver and Crystal, Misty remains in Cerulean while Bill has moved to the Johto region. A thief who stole an integral part of the power plant's generator hides out in the Cerulean Gym while Misty is away on a date. Interestingly, the couple who's house is broken into during your earlier adventures has opened a new police station in Cerulean, and their Diglett has happily learned to dig.