to open the door of the 7th gym!
The Secret Key that you get in the Pokemon Mansion is used to enter the Cinnabar Gym.
The secret key is hidden in the basement of Pokemon Mansion which is located on Cinnibar Island.
On cinnabar island but you need to get the secret key in Pokemon mansion first.
You need the secret key which is found in Pokemon mansion which is also on cinnibar island.
Yes. The Secret Key is needed to open the Cinnabar Island Gym. The Secret Key can be found on a table in the northwestern room of the basement.
After solving the puzzle in tanoby key you can go inside the tanoby chambers and capture the Pokemon Unown.
You need to go through the Pokemon mansion and beat all the trainers. At the last one you get the "secret key" to Blaine's gym.
The key to the gym
You will need to use the Secret Key which is hidden in the basement of Pokemon Mansion which is located on Cinnibar Island.
First surf down from pallet town then go into Pokemon mansion and get the secret key then go into the 7th gym and beat blaine.
the key is in the basement
you get it by searching for it for yourslf