Letterboxing

Letterboxing combines artistic ability with "treasure-hunts" in parks, forests, and cities around the world. Participants seek out hidden letterboxes by cracking codes and following clues. The prize: an image from a miniature piece of art known as a rubber stamp—usually a unique, hand-carved creation. Letterboxers stamp their discoveries in a personal journal, then use their own rubber stamp, called a signature stamp, to stamp into the letterbox's logbook.