Clue Town Books are a series of ready-to-solve scavenger hunts located in walkable areas of Atlanta, Georgia (Piedmont Park, Oakland Cemetery, and Downtown Decatur). Hunters use landmarks to solve puzzles. The solutions to those puzzles reveal how to get to the next checkpoint.
The hands-on activity for Mini Maker Faire is a mini-hunt at the booth, solving a game or two that lead hunters to a hidden QR code (or cookie) at the table. I would also be excited to explain to attendees my process for creating scavenger hunts.