Route 10 · Lavender corridor

Pokemon Yellow Rock Tunnel & Flash

The dark cave between Route 10 and Lavender is a ladder puzzle, not a maze of treasures. Grab HM05 Flash from the Route 2 Gate aide (10 owned) after the Boulder Badge, teach a mon, then follow the 5-step ladder route below with live map links.

Flash: Route 2 Gate 10 owned species Boulder Badge Flash optional but best 5 ladder steps Exit → Lavender
Zubat
Zubat spam
Onix
Onix threat

Fast answer

Flash helps; ladders win

Yellow does not softlock you without Flash—you can walk the dark cave—but visibility is awful. Get HM05 early (aide needs only 10 owned), earn Brock’s badge for outdoor Flash, then run the ladder chain from the north Route 10 entrance to the Lavender-side exit.

HM05Flash gift
10Owned for aide
5Ladder steps
4Wild species

HM05

How to get Flash

Route 2 Gate10 owned

Oak’s aide gift

On the gate between Viridian Forest and Pewter / Diglett’s Cave side traffic, the aide checks for 10 owned species and gives HM05 Flash.

Gate map HM05 item Pokédex owned
Teach itParty slot

Who should hold Flash?

Partner Pikachu can learn Flash—handy so you do not waste a full HM slave early. Butterfree, Abra line, and many Electric/Psychic mons also work.

HM slaves Team Planner
OptionalDark run

Crossing without Flash

Possible with this page’s ladder markers and the interactive map. Expect more missteps and trainer bumps. Repels help if you skip light.

1F map Walkthrough

Interactive tool

Ladder route to Lavender

Follow the numbered ladder chain. Mark steps done; progress stays in this browser.

Step 1 / 5

Wild tables

Rock Tunnel encounters

Yellow’s tunnel is lean—no unique floor items—so you only fight for experience and dex entries. Open Catch Planner for exact slot math.

Pokémon Floor Levels Slot % Links

Compatibility

Who can learn Flash

Survival tips

Before you enter the dark

Heal first

Use the Rock Tunnel Pokémon Center on Route 10. Trainers and Onix can chunk underleveled parties.

Fighting / Water / Grass answers

Geodude and Onix hate Fighting, Water, and Grass. Machop can be awkward for pure Normal teams—bring coverage.

Repels optional

If you only care about Lavender access, repels cut Zubat noise. Turn them off if you still need Machop or Onix dex entries.

After Lavender

Tower, Fuji, and the Poké Flute chain open next—see the Flute/Snorlax guide once you exit south.

Checklist

Tunnel prep tracker

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FAQ

Rock Tunnel questions

Where is Flash in Pokemon Yellow?

HM05 from Oak’s aide in the Route 2 Gate after 10 owned species.

Can I finish Rock Tunnel without Flash?

Yes. Use the ladder steps and map pins on this page; visibility is just worse.

Which entrance should I use?

Story routing usually enters from Route 10 north and exits toward Lavender on the south side of 1F.

Are there items inside Rock Tunnel?

In Yellow, the tunnel has no unique item pickups on the main ladder route—do not detour expecting treasure.

What is next after Lavender?

Pokémon Tower, Mr. Fuji, and the Poké Flute unlock—see the Flute & Snorlax guide.

Continue

Beat BrockBoulder Badge for outdoor Flash. TM & HM listHM05 with every machine. HM slavesWho should hold Flash long-term. Poké Flute & SnorlaxWhat Lavender unlocks next. Fly destinationsRoute 10 is a fly warp later. Legendary locationsPower Plant / birds after mobility. Catch PlannerExact cave encounter rates. Team PlannerCoverage for Rock and Fighting. WalkthroughStory order into Lavender. My RunTrack badges and objectives.