cerulean city kanto.hope it helps!
Where you find Misty.
she is at cerulean cape
misty will be a gym leader in HeartGold and SoulSilver
Misty is somewhere on Route 25.
Find a pikachu in the forest Train it until level 60-70 Teach it thunderbolt (or another electric type move) Shock Misty Easily
it is in misty's gym press a on the life savers
After you beat the Cerulean Gym it is up on the cape where you find Misty. You have to see it at other points during the game though
Beat the rest of the gym leaders first.
Travel to the end of Route 25 and she will be standing there.
you need to first go to the power plant and find out that there was a thief and then find him in Misty's gym and then interrupt misty's date on route 25
She is in Cerulean City, in the Cerulean Cape. You will have to battle your way there however.
You find her at the Cerulean Cape after you have defeated/caught Suicune from 4:00 PM to 5:59 PM.