Appendix:Red and Blue walkthrough/Section 17

Route 4

Go west from the entrance of the Cerulean Cave to the Route 4 to meet a trainer that was unaccessible without Surf.

Trainers
Trainer Pokémon Lass Reward: $465 Paras Lv.31 No item Paras Lv.31 No item Parasect Lv.31 No item

Cerulean Cave

As Champion, you can now access Cerulean Cave, which was previously off-limits because of the powerful Pokémon inside. This is where Mewtwo fled after destroying the research facility on Cinnabar Island.

This is a treacherous, sprawling cave, so make sure that you are well-prepared. Stock up on Ultra Balls and bring the Super Rod along, too. Bring a Pokémon that can use Surf, and pack that Master Ball if you still have it. Mewtwo is one tough fighter, even harder to catch than the legendary birds, so you're in for a long battle if you've used it already. Head north to Route 24 and surf south along the river to reach the cave.

Available Pokémon

1F Pokémon Games Location Levels Rate Golbat R B Y Cave 46 25% Magneton R B Y Cave 46 15% Hypno R B Y Cave 46 15% Arbok R B Y Cave 52 10% Sandslash R B Y Cave 52 10% Venomoth R B Y Cave 49 10% Dodrio R B Y Cave 49 10% Parasect R B Y Cave 52 5% Kadabra R B Y Cave 49 5% Raichu R B Y Cave 53 4% Ditto R B Y Cave 53 1% Fishing Magikarp R B Y Fishing Old Rod 5 100% Poliwag R B Y Fishing Good Rod 10 50% Goldeen R B Y Fishing Good Rod 10 50% Slowbro R B Y Fishing Super Rod 23 25% Krabby R B Y Fishing Super Rod 23 25% Seadra R B Y Fishing Super Rod 23 25% Seaking R B Y Fishing Super Rod 23 25% A colored background means that the Pokémon can be found in this location in the specified game. A white background with a colored letter means that the Pokémon cannot be found here. 2F Pokémon Games Location Levels Rate Dodrio R B Y Cave 51 25% Venomoth R B Y Cave 51 15% Kadabra R B Y Cave 51 15% Electrode R B Y Cave 52 10% Marowak R B Y Cave 52 10% Rhydon R B Y Cave 52 10% Wigglytuff R B Y Cave 54 5% Chansey R B Y Cave 56 5% Ditto R B Y Cave 55-60 5% A colored background means that the Pokémon can be found in this location in the specified game. A white background with a colored letter means that the Pokémon cannot be found here. B1F Pokémon Games Location Levels Rate Rhydon R B Y Cave 55 25% Electrode R B Y Cave 55 15% Marowak R B Y Cave 55 15% Raichu R B Y Cave 64 10% Parasect R B Y Cave 64 10% Chansey R B Y Cave 64 10% Ditto R B Y Cave 63-67 10% Arbok R B Y Cave 57 5% Sandslash R B Y Cave 57 5% Fishing Magikarp R B Y Fishing Old Rod 5 100% Poliwag R B Y Fishing Good Rod 10 50% Goldeen R B Y Fishing Good Rod 10 50% Slowbro R B Y Fishing Super Rod 23 25% Krabby R B Y Fishing Super Rod 23 25% Seadra R B Y Fishing Super Rod 23 25% Seaking R B Y Fishing Super Rod 23 25% Special Pokémon Mewtwo R B Y Only one 70 Only one A colored background means that the Pokémon can be found in this location in the specified game. A white background with a colored letter means that the Pokémon cannot be found here.

Items

1F Item Location Games Max Elixer On the north-central riverbank  R  B  Nugget On the northwest rock platform  R  B  Rare Candy On the crumbling boulder on the central platform (hidden)  R  B  Full Restore On the southwest riverbank  R  B  2F Item Location Games PP Up East side of the floor  R  B  Full Restore Center of the floor  R  B  Ultra Ball In the southwest corner  R  B  B1F Item Location Games Max Revive On the north-central rock platform  R  B  Ultra Ball ×2 On the central rock platform On the crumbling boulder on the northeast platform (hidden)  R  B

Cerulean Cave, 1F

Cerulean Cave, 2F

Cerulean Cave, B1F

1F

Walk up onto the rock platform and climb the ladder to the second floor.

2F

Loop around to the east, grab the PP Up, and take the ladder in the northeast back to the first floor.

1F

Go down the stairway and surf to the west. Grab the nearby Max Elixer, and climb onto the rock platform just west of that. Pick up the Nugget and climb up the ladder.

2F

Head east through the maze to find a Full Restore, then continue on to find the next ladder.

1F

Go west and surf across the water for another Full Restore, then climb back onto the rock platform. Follow the southern trail to the next ladder.

2F

Pick up the Ultra Ball, then follow the trail to the ladder in the northwest.

1F

Take the next ladder down to the basement floor.

B1F

Head northeast from the ladder, and grab the Max Revive from the north-central rock platform. Follow the trail to the southwest, and climb up onto the central rock platform to collect another Ultra Ball. Surf across the water and cut across the rock platform in the northeast. Surf south to find Mewtwo alone on its island.

Mewtwo

Not only is it the strongest Pokémon in the game, but it's already at level 70! Be sure to save the game before approaching it, as you have only one chance to catch it. Mewtwo can restore its health nearly a dozen times with Recover, and is only vulnerable to Bug-type attacks. However, the three damage-inflicting Bug-type moves are fairly weak. It may be better to use the legendary birds, as they are nearly Mewtwo's equals in terms of power. freezing it with Blizzard, Ice Beam, or Ice Punch is the best way to catch it, as it cannot attack or recover.

Type: Psychic Unknown Mewtwo Lv.70 Barrier Psychic   --       Swift Normal   --       Psychic Psychic   --       Recover Normal   --

With Cerulean Cave cleared, the storyline is now complete. Even though there are no more Gym Leaders to defeat, you still have a task to finish: completing the Pokédex for Professor Oak. If you manage to do it, you can show it to the Game Freak employees in Celadon for your reward.

This article is part of Project Walkthroughs, a Bulbapedia project that aims to write comprehensive step-by-step guides on each Pokémon game.