Red & Blue Cerulean Cave
A flooded cave near Cerulean City, open only after the Pokemon League, where Mewtwo lurks past Kanto's toughest wild Pokemon.
Cerulean Cave is in Kanto, with its entrance in Cerulean City. In the story it comes after Indigo Plateau.
CERULEAN CAVE MAP
Surf is the gate here, since the lowest of the three floors is open water. Ladders link the upper levels above the underground lake.
Cerulean Cave Walkthrough
1F
- From the entrance, walk up the plateau's east side, then SurfMoveSurfWaterClassSpecialPower95Accuracy100%PP15A strong water-type attack. east, north and west to take the Max ElixirMax Elixir1F, southwest of the northeasternmost ladder southwest of the northeasternmost ladder.
- Land on the north shore, pick up the NuggetNugget1F, in the northwest area of the floor in the northwest and climb that plateau's ladder.
- Take the Full Restore northwest of the center of 2F, where the ladder on the northwest plateau leads. Its twin sits in the southwest of 1F.
- Wind east to the ladder down, search the rock on the plateau east of that twin for a hidden Rare Candy, then SurfMoveSurfWaterClassSpecialPower95Accuracy100%PP15A strong water-type attack. west for the twin.
Max Elixir
Nugget
Rare Candy2F
- SurfMoveSurfWaterClassSpecialPower95Accuracy100%PP15A strong water-type attack. back to the plateau north of the entrance, climb its ladder from 1F and wind south and east to the PP Up in the east of 2F.
- Return down, SurfMoveSurfWaterClassSpecialPower95Accuracy100%PP15A strong water-type attack. the north water west and the west lake south, then climb the southwest ladder and wind north to that pocket's far west ladder.
PP UpB1F
- From the landing, head east along the north side for the Max Revive in the northeast of B1F, then wind back to the lake.
- SurfMoveSurfWaterClassSpecialPower95Accuracy100%PP15A strong water-type attack. it south, east and up its east arm, walk round to the next pool, then SurfMoveSurfWaterClassSpecialPower95Accuracy100%PP15A strong water-type attack. it west, south and east to the ledge.
- Save, then walk north to battle MewtwoDoes not evolve: knocking it out removes it for good.
Max RevivePokemon Encounters
These are the highest-level wild Pokemon in Kanto, mostly in the high 40s through the mid 60s, so bring your strongest Poke Balls. Mewtwo waits at the very bottom at level 70.
Old Rod1
Good Rod2
Super Rod4
Old Rod1Good Rod2Super Rod4Mewtwo
ITEMS
Kanto's hardest dungeon carries loot to match: Max Revive, Max Elixir, two Full Restores, an Ultra Ball, and a PP Up for your strongest move. A Rare Candy waits out of sight in the depths.
Rare Candy
Causes a level-up and raises happiness.
Rare Candy
Causes a level-up and raises happiness.
PP Up
Raises a move’s max PP by 20%.
Full Restore
Restores HP to full and cures any status ailment and confusion.
Ultra Ball
Tries to catch a wild Pokémon. Success rate is 2×.
Max Elixir
Restores PP to full for each move.
Nugget
Sell for 5000 Pokédollars, or to Ore Collector for 10000 Pokédollars.
Max Revive
Revives with full HP.
Cerulean Cave Guide
Become Champion first. The cave, known in these games as the Unknown Dungeon, stays blocked by a Pokemon Trainer in Cerulean City until you clear the Elite Four. Once he steps aside, a short Surf across the pond is all that's left between you and the entrance.
It's on the bottom level, across a stretch of water. This is what the Master Ball from Silph Co. was meant for, since at level 70 Mewtwo outclasses anything else in these games and you get one shot at it. Bring your strongest team and a full bag of healing before you Surf over.
Rock Tunnel is the only one you can't see inside. Mt. Moon, the Seafoam Islands, Victory Road, and the Unknown Dungeon all light themselves, so Flash is just a convenience there. Claim HM05 Flash from Oak's Aide in the Route 2 gatehouse once you've caught ten different species.
Victory Road and the Seafoam Islands both gate progress behind it. Victory Road uses boulder-on-switch puzzles to open doors, while Seafoam needs you to shove boulders into holes to kill the water current. You earn HM04 Strength from the Safari Zone Warden after returning his Gold Teeth.
Worth it when you're only passing through. Repels turn off any encounter weaker than your lead Pokemon, which makes a high-level run through Golbat-infested Victory Road far quieter. Just pull the Repel back off when you actually want a rarity like Chansey or Clefairy to appear.