To get to know this, you have to be well versed with the cheat-codes of the Pokemon leafgreen. You need to go to the national pokedex by catching 60 Pokedon. Then after beating the elite four, you can catch 386 pokemon in a particular place. After going to each and every island, go to the safari zone and then go back out. Go back in and then go to the very back of the safari zone and you will see a cave. When you go through it, the time for the safari zone will be cancelled.

Xtreme cheats is a website which contains all the possible Pokemon LeafGreen cheats, hints and codes which can help you play the game smoothly and smartly. For more information, go to lorn.comgameboyadvance_cheats/12575_pokemonleafgreen.html .