Big Walk Tunnels Guide
Unlock the tunnel network through the Yellow route, find its entrances and get Big Tunnel.
- 🔑 Yellow route destination
- 🕳 Underground network
- ↕ 4 colored access points
- 🏆 Big Tunnel achievement
Check My Tunnel AccessShow Tunnels on Map
Tunnel Access Status
- Yellow Key released
- Key cutters
- Finished key placed
- Tunnel network open
NEXT
Finish the Yellow source requirement.
How to Unlock the Tunnels
- 1Yellow Route
- 2Yellow Key released
- 35 Cutters
- 4Finished Yellow Key
- 5Tunnel Destination
- 6Tunnel Network Open
The canonical Yellow route leads to the tunnel unlock destination. Finishing the Train or Chairlift first is not part of this unlock.
Your tunnel state is saved on this device and shared with the Yellow route and 100% tracker.
Tunnel Access Status
These four checks name the one thing still standing between you and the tunnel network.
Has the Yellow Key been released?Not yet
Have all five Yellow cutters been completed?0 / 5
Tap the placed key or the open network once you have done it. Progress is saved on this device and shared with the rest of the site.
NEXT
Finish the Yellow source requirement.
The Yellow Key has not been released yet. Tunnel access belongs to the Yellow route, so the source has to hand the key over first.
Your next action
Release the Yellow Key.
Why Are the Tunnels Still Closed?
Work down this list. Each row is one Yellow-route state, not a generic “finish earlier transport first” step.
Yellow source incomplete
Your next action
The Yellow Key has not been released from its source.
Finish the Yellow source requirement.
A Yellow cutter is still missing
Your next action
The released key has not passed every cutter yet.
Go to the first incomplete Yellow cutter.
The Yellow Key is still unfinished
Your next action
Five cutters are required before the key is in its finished state.
Complete the remaining Yellow cutters.
The finished key has not been placed
Your next action
All five cutters are done, but the finished key has not reached the tunnel destination.
Take the finished Yellow Key to the tunnel destination.
Key placed, gates still closed
Your next action
The Yellow route is finished, so this is not a route problem any more.
Check the four colored access gates in game and use the one that opens.
How to Unlock the Tunnels
The unlock is the Yellow Big Key route, end to end. In order:
- 1
Release the Yellow Key.
- 2
Complete all five cutters.
Yellow Cutter 1Yellow Cutter 2Yellow Cutter 3Yellow Cutter 4Yellow Cutter 5
- 3
Take the finished key to the tunnel destination.
- 4
Open the tunnel network.
Releasing the Yellow Key is only the beginning. Nearby Yellow puzzles are not a substitute for the five cutters or the destination.
Where Are the Tunnel Entrances?
The Yellow route has the activation destination, but once the network opens there are several colored access points around the island.
Yellow unlock point
The finished Yellow Key goes to this one destination. Opening it is not the same thing as the underground network it switches on.
Colored access points
Four verified gates — red, green, blue and yellow. Once the network is open, the same gate works as an entrance or an exit.
Tunnel Network
One transport system with four colored access gates. Where each gate leads underground is not published as a route order.
Where Does Each Tunnel Go?
Pick a gate to see what is verified for it. The color of a tunnel does not prove which area it leads to, so no destination is guessed from the color alone.
This is a schematic of the four verified gates, not a map of the underground geometry. No unverified corridors are drawn.
Colored tunnel gate
Red Tunnel Access
Status
Locked
Map position
Marked on the world map
Underground route
Not published yet.
Show on World MapHow to Use the Tunnels
- 1Unlock the Yellow route.
- 2Enter an opened tunnel entrance.
- 3Follow the in-game route and signage through the network.
- 4Exit through an available access point.
Community guides recommend using a flashlight because the tunnels are dark. Treat that as a tip rather than a requirement.
What Do the Tunnels Do?
They give your group an underground route between several parts of the island.
The tunnels are a transport system of their own, not a faster version of the Train or the Chairlift, and not a late-game gate unless a later dependency is verified.
Tunnels, Train and Chairlift
Each transport is opened by its own Big Key route. The full comparison lives on the Transport hub.
- Chairlift· Green
- Train· Blue
- Tunnels· Yellow
- Open the Transport Hub
Big Tunnel Achievement
Opening the tunnel network is not the achievement. Once the network is open, actually enter one of its tunnel entrances.
🏆 Requirement
Enter a big tunnel.
Standing at the mouth of the tunnel is not entering it. The full trigger, the entrances that count and the fixes live on the achievement page.
Big Tunnel or Train Tunnel?
Big Tunnel
The underground network the Yellow route opens. Walking into it is what fires the medal.
Railway tunnel
Part of the Train route. Riding the Train through it is a different system and does not fire Big Tunnel.
Secrets Inside the Tunnels
Shiny Makeover Room
The makeover room with the metallic finishes sits inside the tunnel network. The full route, the paint choices and the achievement checks belong to the Big Makeover guide.
Get Shiny GuideWhat Should I Do After Unlocking Tunnels?
Yellow being complete does not pick the next route for you. Use your current progress to see which unfinished route actually matters.
What Should I Do Next?Unfinished Red, Green or Blue, the Black Tower, or later progression only appear when that dependency is true for you.
Tunnel FAQ
How do I unlock the tunnels?
Finish the Yellow Big Key route: release the key, pass it through all five cutters, then place the finished key at the tunnel destination.
Do I need the Train first?
No fixed Train → Chairlift → Tunnels sequence should be assumed. The tunnel network belongs to the Yellow route.
I finished Yellow Tower. Why are the tunnels still locked?
Releasing the Yellow Key is only the beginning. Complete all five cutters and place the finished key at the tunnel destination. Yellow Area Guide
How many tunnel entrances are there?
Four colored access gates are verified: red, green, blue and yellow. Each one works as an entrance or an exit. Access point details
Where do the red, green, blue and yellow tunnels go?
A destination is shown only where one has been verified. The color of a gate is not treated as proof of where it leads. Access point details
How do I get Big Tunnel?
Enter an open big tunnel. The official requirement is simply to enter a big tunnel. Big Tunnel
Does opening the tunnels automatically unlock Big Tunnel?
No. Unlocking the network is not the trigger — you have to walk inside a big tunnel. Standing at the entrance does not count. Big Tunnel section
Are the Train tunnels the same thing?
No. Railway tunnels belong to the Train route. Big Tunnel is the underground network the Yellow route opens. Train Guide
Is the shiny makeover room inside the tunnels?
The makeover room sits inside the tunnel network, but its route, paint choices and achievement checks belong to the Big Makeover guide. Big Makeover Guide
Are the tunnels required for the ending?
The transport network and ending progression should be treated as separate systems unless a specific late-game dependency is verified. What Should I Do Next?
Related
Yellow Area
The Yellow Key, its five cutters and the tunnel destination.
Big Key
Every ordinary Big Key route, including Yellow.
Big Tunnel
The achievement for entering a big tunnel.
Interactive Map
Yellow route and tunnel pins as separate layers.
Train
Blue-route destination. A different transport system.
Chairlift
Green-route destination. A different transport system.