Go to kanto and collect the eight badges there
professor oak gives it to u after u got all 16 bages
In Pokémon HeartGold, you can gain entry into Cerulean Cave once you've defeated Blue.
i think u have to get all the 16 gym bages and then talk 2 pror oak if im wrong feel free to correct
you need all 15 gym bages then go their have fun but get your starter pokemon forom the professer at paallet town first
beat red and go to prof. oak. he will give you a choice of charmander, bulbasaur, or squirtle. you also need all 16 bages
well you have to go to victory road go in the place in front of you turn right and if you have all bages he might let you in if not turn left and talk to the other man he will not let you past unless you have all jotho bags but he still won't let you past so you have to have all jotho and kanto bages and he will let you past both of them
get all 8 gym bages
Beat Clair, The dragon master. (shes the gym leader in blackthorn city). :-) Get all eight bages and then talk to professor elm
Yes you can do that by getting really strong Pokemon like all your Pokemon have to be level 40-50 then you can beat all gym leaders with no sweat
Then you have to face the Elite Four
Get all eight badges then go see professor elm and he'll give it to you!
u get it from blue once you get all eight gym badges in kanto