That would be Castelia city.
Shaga in Pokemon Black, Iris in Pokemon White.
The third gym leader in Pokemon Sapphire is Wattson and he is located in Mauville City.
he is in the SunnyShore City Lighthouse after the black out.The last Gym leader is located in Sunyshore city. His name is Volkner and he is a master of electric type Pokemon. Look out, even if you have ground type Pokemon, because his Pokemon may know ice moves that can wipe out ground type Pokemon.
in the city with skyla being the gym leader it is right of pokemon center:)
The 8th gym leader is Drayden, who uses Dragon-type Pokemon. You face him in Opelucid City.
Driftveil City. Gym Leader Clay!
you find her in nacrene city and she has normal type Pokemon
Roxanne is the leader of the Rustboro City gym.
defeat the gym leader in the city it is in then you can go to in it should be the city After driftvil
The Fighting type gym leader, Maylene, is located in Veilstone City.
The 5th gym leader in Johto is Chuck. He is located in Cianwood City.
You battle the 8th gym leader, Clair, at Blackthorn City.