you can get to the 8th gym after you defeat team galactic and defeated 7th gym.
The eighth gym leader in Pokemon platinum is the one in sunny shore city.
in sunyshore city
in sunnyshore
you must beat the eighth gym leader and he will give you the badge.
The eighth gym leader of Sinnoh, Volkner, returns to battle you again in Platinum after you beat the Elite Four. When you get to battle frontier, you and your rival have a double battle against Volkner and Flint, an Elite Four member.
You go to SunyShore City, Then go on that glass sorta thing and it's up there somewhere!
you have to battle all the trainers and repeat it ..................... Im sure you can do it.
The fourth gym in platinum is the veilstone gym
The eighth gym leader is Claire in Blackthorn City
it depends............................WHICH GAME??!!??!!
The eighth gym leader is in Viridian City. It is the team rocket's leader!
Defeat the eighth gym leader.