Big Walk Yellow Tower Guide: Unlock the Tunnels
Complete the Yellow key route and open the underground tunnel network for faster travel and later secret cleanup.
Before heading to Yellow
Red Tower's map makes the route easier, and Green Tower's chairlift reduces the climb, but neither is a strict requirement once the relevant areas are reachable. Bring a light because the reward is an underground travel system.
Unlock sequence
- Gather five physical rewards from unfinished challenges.
- Place them in the Yellow receiver.
- Carry the released key through every Yellow cutter.
- Use the finished key at the tunnel mechanism.
- Enter the now-open underground route to confirm the system and unlock Big Tunnel.
Why the tunnels matter later
They provide shortcuts between distant regions and are involved in post-progression exploration, including the route associated with getting shiny. If you are only standing at a tunnel entrance and it remains closed, the Yellow key route is not complete.
Prepare for the underground route
Bring at least one lantern, keep a communication tool with each subgroup and choose a named entrance as the fallback meeting point. Tunnels are useful shortcuts only when players agree where they will emerge; otherwise the network can separate the party more effectively than walking outside.
Entering an active tunnel should trigger Big Tunnel. If the door remains shut, trace the Yellow cutter arrows again and compare the key shape at the last machine. Repeating five tower challenges will not fix a key that was never fully cut.
Sources checked
- Big Walk walkthrough and route hub — Yellow progression checkpoint and tunnel role
- Community guide index — tower flexibility and tunnel guide cross-check