It is in Fuchsia City, which is West from Celedon using the Cycling Road (so you need a bike). Or you can take the bridge network South of Lavender Town. Either way, you will need a Pokeflute for Snorlax, whom you should catch because he is a beast with Rest, Sleep Talk, Return, and Hyper beam.
you can either go to fuschia city or saffron city because you can acess two gyms by the time you have the rainbow badge
In Pokémon Pearl, the fifth Gym Leader is Fantina so you can battle her for her Badge in Hearthome City.
The 5th Gym is in Cianwood City in Pokemon Gold, Silver, and Crystal.
Driftveil City. Gym Leader Clay!
Vermilion city.
Fantina is the 5th gym Leader in Hearthome the Ghost type gym.
Koga, he is in fuschia city, he uses poison Pokemon
The 5th Gym is in Cianwood City.
The 5th Gym is in Cianwood City.
The 5th gym is the Fuchia city gym Gym leader Koga
The 5th Gym is in Cianwood City in Pokemon Silver, Gold, and Crystal.
the 5th gym is in hearthome city
The fifth gym is in petalburg city
Cianwood city.
The 5th Gym is in Cianwood City in Pokemon Gold, Silver, and Crystal.
beat the gym
Pastoria city
Driftveil City. Gym Leader Clay!
In petalburg city.