Pokemon FireRed and LeafGreen
Pokemon FireRed and LeafGreen

Cinnabar Island Mansion & Secret Key

Locate the Secret Key within the Cinnabar Island Mansion in Pokémon FireRed and LeafGreen. Navigate the mansion's maze to find the key and challenge Gym Leader.

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Cinnabar Island Mansion & Secret Key

Welcome to Cinnabar Island! Before you can challenge Blaine, the Gym Leader, you'll need to find the Secret Key to open his Gym. This key is hidden deep within the Pokémon Mansion, a dilapidated building located on the northern side of the island. Prepare for a maze-like structure filled with Trainers, wild Pokémon, and journal entries that shed light on the creation of Mewtwo!

Navigating the Pokémon Mansion

The Pokémon Mansion is a four-story building (including the basement) with numerous locked doors and hidden switches. You'll need to press switches to open specific doors, often requiring you to backtrack. Wild Pokémon encounters are frequent here, so make sure your team is well-prepared with plenty of healing items. Common wild Pokémon include:

  • Rattata
  • Raticate
  • Grimer
  • Muk
  • Koffing
  • Weezing
  • Ditto

Ditto can be particularly useful for breeding later in the game, so consider catching one if you don't already have a good one.

First Floor Exploration

  1. Upon entering, head right and then up. You'll find a staircase leading to the 2F. Ignore it for now.
  2. Continue right from the entrance, then go down. You'll enter a room with a Trainer.
  3. Battle Burglar Arnie (Level 34 Growlithe, Level 34 Ponyta).
  4. After the battle, head through the door to the right.
  5. In this next room, you'll find a Max Repel on the table.
  6. Exit this room and go back up. You'll see a statue. Interact with it to find a hidden switch. Pressing this switch will open a door on this floor.
  7. Go left from the statue and through the newly opened door.
  8. In this area, go down and then left. You'll find a Carbos.
  9. Now, head back to the entrance area and take the stairs up to the 2F.

Second Floor & Journal Entries

  1. On 2F, head right and then up. You'll find a room with a journal entry. Read it to learn about Mew's discovery.
  2. Continue right from this room. You'll encounter Scientist Ted (Level 33 Magnemite, Level 33 Voltorb, Level 33 Magneton).
  3. After the battle, head down. You'll find another statue. Press the switch on it. This opens a door on the 1F, but also closes another.
  4. Go left from the statue and then down. You'll find a Full Restore.
  5. Now, head back to the stairs you came up from and go down to 1F.

Back to the First Floor

  1. On 1F, head left from the stairs. The door that was previously closed should now be open.
  2. Go through this door and proceed left. You'll find a Calcium.
  3. Head back to the stairs and go up to 2F again.

Third Floor Access

  1. On 2F, go right from the stairs. Then head up and left through the open door.
  2. You'll find another set of stairs leading to 3F. Take them.

Third Floor & The Secret Key

  1. On 3F, head right. You'll find a room with another journal entry, detailing the birth of Mewtwo.
  2. Continue right and then down. You'll encounter Burglar Simon (Level 38 Ninetales).
  3. After the battle, head through the door to the right.
  4. In this room, go down. You'll find a Max Elixir.
  5. Now, head back to the room where you fought Burglar Simon. Go left and then down. You'll find a statue. Press the switch. This opens a door on the 3F and closes another.
  6. Go right from the statue and then down. You'll find a TM14 (Blizzard).
  7. Head back to the statue and go left. The door that was previously closed should now be open.
  8. Go through this door and then down the stairs to the 2F.

Back to the Second Floor (Briefly)

  1. On 2F, head left and then down. You'll find a Rare Candy.
  2. Now, head back up to 3F using the same stairs.

Basement Access & The Secret Key

  1. On 3F, go right from the stairs, then down, and then left. You'll find another set of stairs leading to the Basement. Take them.
  2. In the Basement, head left. You'll find a Full Heal.
  3. Continue left and then down. You'll encounter Scientist Ivan (Level 33 Electrode, Level 33 Weezing, Level 33 Electabuzz).
  4. After the battle, head left. You'll find the final journal entry, confirming Mewtwo's destructive power.
  5. From the journal, head down. You'll find a statue. Press the switch. This opens the final door.
  6. Go right from the statue and then down. You will finally find the SECRET KEY!

With the Secret Key in hand, you can now exit the Pokémon Mansion. You can either backtrack through the mansion or use an Escape Rope/Dig if you have one. The Secret Key automatically unlocks the Cinnabar Gym, allowing you to challenge Blaine and earn your seventh Gym Badge!