If its the one nearsaffron city, first you have to beat the elite four and the champion. then use surf to get to the cave and he should let you in.
Press the secret button behind the poster in the Game Corner.
Secret of the Cardboard Rocket - 2003 was released on: USA: 2003 (limited)
There is no secret behind DragonFable.
it opens doors in the secret rocket base in celdon city
Nothing
you have to sequence the panels on the floor the trick is to battle the rocket member near one the floor panels and when you finally battle that rocket member you be still be on the panel then walk off the panel behind the rocket and you find a poke'ball filled with the secret card key
It is toilet paper.
There is a Rocket Grunt gaurding a poster in the back of the Game Corner in Celadon City. Talk to him, and he will attack you. After defeating him, he will say: "There's no switch behind the poster!" Obviously, there is. Touch the poster, and flip the switch... SECRET STAIRCASE TO THE ROCKET HIDEOUT!
Secret code : PROFPURPLEX6
It is underground
there's a SECRET Hideout on the 5th Island, but you nee two passwords to enter You can get the two passwords from the Rocket Members on the Island, have a nice day
what!?