You open doors with the head things
The secret key is in the Pokemon mansion (Cinnabar Island) in the basement.
get the key
You will find it in the Pokemon mansion on cinnabar island.
you have to get a key in the Pokemon mansion
you have to find it inside the Pokemon mansion located on cinnabar island
Look for it.... Everyone else did
no. 2
You have to find the key to the Cinnabar Gym there.
in the bottom of the Pokemon mansion
the cinnabar key is in a poke ball that is in the Pokemon mansionin the last floor of cinnibar gym.
The Secret Key that you get in the Pokemon Mansion is used to enter the Cinnabar Gym.
you have to go into the old haunted mansion in order to get the key for the gym