Part 7: Got the Poké Flute — Pokémon Tower

Mr. Fuji gives you the Poké Flute once you rescue him at the top of Pokémon Tower, where the ghosts need the Silph Scope, found in the Rocket Hideout under the Celadon Game Corner. The flute wakes the Snorlax blocking Routes 12 and 16, which is the way south to Fuchsia.

Got the Poké Flute — Pokémon Tower opens 8 areas. There are 49 trainers standing in them.

Where to go

1. Route 13

   Wild: Magikarp 100% · Lv 5, Slowpoke 95% · Lv 15, Horsea 70% · Lv 15-20, Goldeen 50% · Lv 10 +11 more

   Trainers: Beauty Lv 27, Beauty #2 Lv 29, Biker Lv 28, Bird Keeper Lv 29, Bird Keeper #2 Lv 25, Bird Keeper #3 Lv 26 +4 more

2. Route 14

   Wild: Bellsprout 30% · Lv 26-28, Oddish 30% · Lv 26-28, Venonat 19% · Lv 24-27, Pidgeotto 10% · Lv 30 +3 more

   Trainers: Biker Lv 29, Biker #2 Lv 26, Biker #3 Lv 28, Biker #4 Lv 29, Bird Keeper Lv 33, Bird Keeper #2 Lv 29 +4 more

3. Route 15

   Wild: Bellsprout 30% · Lv 26-28, Oddish 30% · Lv 26-28, Venonat 19% · Lv 24-27, Pidgeotto 10% · Lv 32 +3 more

   Trainers: Beauty Lv 29, Beauty #2 Lv 29, Biker Lv 25, Biker #2 Lv 28, Bird Keeper Lv 26, Bird Keeper #2 Lv 28 +4 more

   Pick up: TM20 Rage

4. Route 16

   Wild: Doduo 40% · Lv 22-26, Rattata 25% · Lv 23-24, Spearow 25% · Lv 22-23, Fearow 5% · Lv 24 +2 more

   Trainers: Biker Lv 29, Biker #2 Lv 33, Biker #3 Lv 26, Cue Ball Lv 28, Cue Ball #2 Lv 29, Cue Ball #3 Lv 33

   Pick up: HM02 Fly

5. Route 17

   Wild: Magikarp 100% · Lv 5, Tentacool 70% · Lv 5-15, Doduo 50% · Lv 26-28, Goldeen 50% · Lv 10 +5 more

   Trainers: Biker Lv 28, Biker #2 Lv 33, Biker #3 Lv 29, Biker #4 Lv 29, Biker #5 Lv 25, Cue Ball Lv 29 +4 more

6. Route 18

   Wild: Magikarp 100% · Lv 5, Shellder 60% · Lv 20-40, Goldeen 50% · Lv 10, Poliwag 50% · Lv 10 +7 more

   Trainers: Bird Keeper Lv 29, Bird Keeper #2 Lv 34, Bird Keeper #3 Lv 26

7. Safari Zone

   Wild: Magikarp 100% · Lv 5, Goldeen 50% · Lv 10, Poliwag 50% · Lv 10, Dratini 20% · Lv 10 +17 more

   Pick up: TM32 Double Team, TM37 Egg Bomb, TM40 Skull Bash, HM03 Surf

8. Fuchsia City

   Wild: Magikarp 100% · Lv 5, Goldeen 50% · Lv 10, Poliwag 50% · Lv 10, Gyarados 10% · Lv 15

   Pick up: TM06 Toxic

Everything you can have caught by this checkpoint · Open the interactive guide

This game's documentation doesn't say where 4 of its 343 fights happen, so those trainers are on no part of this walkthrough; they are all on the Trainers page. It also doesn't say when Kanto Underground Path opens up, so it is in no part above; it has its own route page.