u have to find the key in the Pokemon mansion i think
In Pokemon FireRed and LeafGreen you can't open a gym.
After obtaining the other 7 badges you return to Viridian City and the gym will be open.
If you mean, "how do I unlock the Gym where he is", you have to go into the mansion and get to the basement. There you will find the key to open the Gym
You get the card key which lets you open the gym which is locked.
You get the card key which lets you open the gym which is locked.
after u beat the gym leader on cynabar Island the gym, that wuz closed the whole time will be open
go to cinnabar island then go into Pokemon mansion go through here to get the secret key which opens the 7th gym.
Because the key to open the door is hidden in the Pokemon Mansion.
there is no gym leader in lavender town
no
beat the gym leader
the thunder gym in in vermillion city