There is a key in Pokemon Mansion (Searching for Mew there on LeafGreen. I know a glitch to get Mew before Misty on Pokemon Yellow without GameShark!) You have to hit the switch on every Statue (At least in LeafGreen. I beat it!) and that Item You NEED to get is the gym's key. Get it. Go to the gym. Use it. Your in.
Pokeglitch20
The 7th gym leader in Pokemon yellow is in Cinnebar Island, which is south of Pallet Town. You need a Pokemon with Surf to get there.
Yea there is the island with the 7th gym on it is an island.
The 7th gym leader is Blaine. He the gym leader of Cinnabar Island gym. He uses Fire type Pokemon and he will give you the TM that contains Fire Blast when you defeat him.
Beat team rocket at Mt moon, Pokemon tower, rocket game corner and silph co. Then get the 7th badge now you can go into the viridian city gym to get the last badge.
there is a key in the Pokemon mansion... you need it to get into the gym... search the Pokemon mansion thoroughly
in the bottom of the Pokemon mansion
beat the 8th gym
In the cinnibar island gym.
Vermilion city
Fuchsia city.
Giovanni
No, sorry!