Once you beat Blane on Cinnabar Island you should receive the seventh trainer badge. You will then travel to Viridian City and walk into the gym where the next gym leader, Giovanni, is waiting for you.
Its in virdian city. The gym leader is Govanni, and he uses ground and fighting pokemon.
beat the 8th gym
Cinnabar Island
It is atchrily the 8th gym. It will open when you get the first 7 gym badges
Battle the 8th Pokemon gym. Mr. Seidshlag
You must go to the Pokemon Gym. Beat the gym leader and he awards you with the 8th gym badge
beat the 8th gym which is in the next town after the town which you live in
It is your rival from Pokemon fire red and leaf green versions.
the bottem left side of vermillion in his gym
viridian city gym. you have to beat all the other seven gyms to unlock this one.
You can obtain the 8th gym badge (the earth badge) in fire red from Giovanni in Viridian City.
Wallace is the 8th gym leader PEOPLE!!!!!!!!!!!