What about a puzzlebox? Like a box for a group to solve puzzles on - puzzles on several surfaces and it slowly unfolds/unboxes as you progress? It could have multiple locks which need creative thinking to solve and once you solve them it unlocks more
Lock with “Blacksmith trick” puzzle to get the key
Lock that must be picked with attached tools
A lock that only opens when some conditions are met (ex: it must be in shadow)
in the inside there could be treasure or like a geocache - leave a treasure/take a treasure thing.
It could be a good thing for a group to make as different groups can work on making different puzzles.