If you are talking about the gym on the island you go into the old building and when you reach the bottom you should find a key of game shark cheats
after beating gym leader blaine
u can find it in Pokemon mansion.
you can catch him inside misy's gym but u need to stay there a long time
You need to go to the Pokemon mansion in Cinnabar Island. Go to the basement and obtain the Secret Key. Then go to the Pokemon Gym and it will be unlocked!
After you beat Sabrina, the 6th gym leader in Saffron City, you can use Rock Smash.
You must beat the seven gym leaders, the elite four, and your rival. Then you have to capture 60 Pokemon to get your Rainbow pass the will allow you to travel to Island 7 in Pokemon FireRed.
go to cicibar island, then go in the biulding right next to the gym and look for secret key. then get out and then you can go in the gym in cinabar island
no
i'm pretty sure you get it from Koga when you beat him(Koga is the 6th gym leader)
mewtwo is in cerulean cave. the cave in in cerulean city, where misty's gym is. mewtwo in hard to catch, though.
Well you go through an underground path and the gym leader you need to know CUT
Saffron city.