To Unlock the Unowns on Leafgreen or Firered go to Seven Island and proceed though the Sevault Canyon as you progress through you should see a cave entrance go inside and complete the boulder puzzle you will get see the screen shaking followed by a message. after that go to the ruins on the southernmost part of the island and simply wonder inside and you will encounter the unown
You cant
gameshark
The key is in the Pokemon mansion.
You have to catch 6o diffrent Pokemon... (good luck)
NO! You can only unlock pal park on platinum, diamond and pearl
either you hack it or you unlock all of the areas and find every single Pokemon
You have to find the key in the abandoned mansion.
its actually the 8th gym so you need 7 badges and then it will unlock
You have to fight the Pokemon league to unlock island four, five, six, and seven.
You need a special item from Nintendo to unlock the item to get to the island where you can catch it.
Yes you can trade leafgreen version Pokemon to another leafgreen version.
You must beat the elite 4!Then you can go to 4,5,6,and 7.