How to get there
Enter Hidden TunnelsOpen on the map- "Enter Hidden Tunnels" from Overworld
About
The Hidden Tunnels are the Old Badongerst Tunnels, a network under Badongerst that Itsop Lloyd says "haven't been used in the better part of a century, it's not exactly common knowledge where the tunnels begin." His advice is to "Look for an entrance in something that survived the fire - the old watchtower would be my guess."
Road bandits and road thieves have moved in, alongside skeletons, zombies and crawlers. The one key you are sure to find here is the Lockbox Key: "Found in the Badongerst Tunnels, it's small and seems like it would fit a chest." The game also has a Badongerst Tunnels Prison Key ("You're not sure you even want to know what's locked up down here...") and a Badongerst Tunnels Chest Key ("This is probably a trap, but treasure is treasure."), though nothing hands either of them out yet.
Spoilers: The Badongerst Blaze
The tunnels are the hideout of the crew Alderman [[Sumner Fugemann]] hired. The letter in his desk confirms "payment for services for a term of 10 years and lodging within the Badongerst Tunnels." Their leader, [[Matchilda Arden]], whom Itsop calls "the sorcerer who started the fire", keeps a lockbox of ill-gotten treasure down here, with a note for her crew:
When I find out which one of you nitwits keeps 'misplacing' my key in the study, I swear I'm gonna turn your hair into a torch
Matchilda
People
Creatures
Numbers count spawn points, not creatures alive at once.
Cavern Fishing Spot
Cavern Netting Spot
Coal Vein
Iron Vein
Lockbox Key
Pond Fishing Spot