Slateport City doesn't have a gym.
he is in stooptopolis city
Pokemon ruby where is the 6 gym
Pokemon platinum is for DS but it is in snowpoint
You will get the Go Goggles from your rival after leaving the 4th Gym in Lavaridge Town. You'll need to defeat Flannery's Pokemon first.
In Mossdeep city I think.....
it is a dragon type Pokemon gym
The third gym leader in Pokemon Sapphire is Wattson and he is located in Mauville City.
fire gym in lavaridge
In sapphire, the 5th gym leader is your dad, in that city after Oakdale.
it is in petalburg near the Pokemon gym
In Pokemon Sapphire, Ruby and Emerald the 7th Gym that's located in Mossdeep City has Psychic type Pokemon.
petalburg
In the gym.
You can with AR.
In the lavaridge town gym.
the grass type gym