The best way to get into the secret rooms in the Pokemon mansion is to find a cheat code for the Pokemon game and install it before playing. You should then be able to easily get into the secrets rooms on floors 2 and 3.
The secret key is in the Pokemon mansion (Cinnabar Island) in the basement.
You simply can't go there.
if you got it from the Pokemon mansion it opens the cinabar Pokemon gym
The Secret Key that you get in the Pokemon Mansion is used to enter the Cinnabar Gym.
Find the secret key in the Pokemon Mansion,( Next to the gym)
The secret key is in the Pokemon mansion (Cinnabar Island) in the basement.
You need Action Replay.
You can't
You simply can't go there.
I dont think that has anything to do with pokemon.......
there is one in hearthhome mansion in one of the rooms
the secret key is in the Pokemon mansion - Celadon city basement
if you got it from the Pokemon mansion it opens the cinabar Pokemon gym
The Secret Key that you get in the Pokemon Mansion is used to enter the Cinnabar Gym.
In Pokémon Red, the secret key is located in the Celadon Mansion, specifically in the northeastern part of the building. To find it, you must navigate through the mansion, avoiding or battling trainers, and search the rooms for items. The key is hidden in one of the rooms on the upper floors, usually found in a trash can near the back. This key allows access to the Gym Leader, Erika's, gym.
With the secret key which is found in the Pokemon mansion.
go to Pokemon mansion where the trophy garden is look in all thr rooms and their will be a book