You will need to work your way to the basement in the Pokemon Mansion, you will then find the Key.
Inside the Pokémon Mansion, the big building to the left of the Gym you want to enter. You have to press buttons on the statues to open and close the doors inside that mansion and reach the key.
the cinnabar key is in a poke ball that is in the Pokemon mansionin the last floor of cinnibar gym.
the mansion you have 2 make it downstairs in the manshion nd down there therell be a pokeball with a key in it nd then you can open the gym but to get downstairs you need 2 use the statues with the eyes that are glowing nd click those to switch the locks on the doors
With the secret key which is found in the Pokemon mansion.
You will find it in the Pokemon mansion on cinnabar island.
The secret key is in the Pokemon mansion (Cinnabar Island) in the basement.
You have to find the key to the Cinnabar Gym there.
you have to find it inside the Pokemon mansion located on cinnabar island
get the key
its in the mewtwo mansion in the basement
Cinnabar Island. To enter you have to find a key in the mansion nearby.
bottom floor of Pokemon Mansion
you find it in deep inside Pokemon mansion i think
You will find the key to the Gym of Cinnabar Island, From the Pokemon Mansion that is on the same island.
you have to get a key in the Pokemon mansion
go tho the big mansion the find the key thare