i had the same problem on soul silver... here is where to get to the 7nth gym in heart gold.
if you played leaf green and fire red it was on islands all the way on the bottom left of map. this place burned down. so now go to seafoam islands (articuno hiding place) and go up the ladder there will be the gym there. and then when you beat the eaith gym go for articuno, zapdos, moltres, kyogre, suicune, latias, latios, celeibi, and much mor! if you need help with any of those legendaries just mail my account
7th gym leader
he is on cinnabar island(fire red) just south if you surf from pallet town.
he is on seafoam islands(ss&hg) just west of cinnabar island and in a cave then up a ladder in the first room.
If you mean Blaine, he is at the seafoam islands, just surf from cinnabar island and you'll find it, but when you're in you go straight there will be a gym (don't go down the stairs on the left).
you have to get to pallet town then go surf keep going down until u reach cinnabar island go talk to the guy ubove the Pokemon center with blond hair hes the 8th gym leader, so go eastto a island go in it and there will be 2 ladersgo down the other one leads u to articuno then the down ladder this the gym, to find articuno go on utube.
blue the gym leader is at the saffron islands i dont know witch one
In fuscha city.
Mahagony Town
you have to go to every gym in kanto a beat all the gym leaders
you go to the harbor and take a boat to the hoenn region
because the main regions are Kanto and Jhoto. Nonetheless you may get a Hoenn starter after beating the game in the Kanto region at Saffron city from Steven
when you get to kanto after the pokemon league you can find it traverling round kanto and you will have to hunt it down hope this helps
You can only reach Kanto and Johto.
Not enough info: which gym leader?
he is Brock. hes in pewter city.
johto and kanto
Yes it is in the kanto region.
To get a Pikachu in Pokemon SoulSilver, you must go to Viridian Forest, which is in the Kanto region.
You can only go to Johto and Kanto in Pokemon Heartgold and Soulsilver
Janine I think
in the kanto region you have to surf a long way then you will be there
misty
it depends if you have been to the kanto region
Route 25 in the Kanto region.
You beat the 6th gym leader.