You leave through the northern exit, but only once you've completed all plot-related events inside Castelia itself.
The eastern exit to Skyarrow Bridge only opens once you defeat the league champion.
In Cerulean gym
North of Cerulean City
after you talk to the director at the power plant.... then go to cerulean gym you will find the team rocker there
goldenrod city and kanto by cerulean city(route 25)
The strongest Wobbuffet you can find in crystal version are in Cerulean Cave, they might be a little hard to find though
Cerulean City, Route 24, Route 25, Route 5, Route 6. After a long walk in the wilderness, you finally arrive in civilization. This is Cerulean City, home of the second Gym. Heal your Pokemon and stock up on items.
Its east of cerulean city use Surf on this route to reach the power plant.
You go to the power plant in Kanto which if you play RBY youd know its by cerulean city.
You can find Misty in Pokémon Crystal in Kanto Region. You will find her north of Cerulean City where she is with the man she is dating.
Find the machine part in the cerulean city gym give that to the guy.
Bill's grandfather lives in Bill's old house on Route 25 which is above Cerulean City.
the only way to get mewtwo is to trade it from Pokemon red,blue,or yellow. in leaf green and fire red he is in cerulean cave cheat codesxD