LETTERBOXING
This hobby is also one to get out and see places you might never otherwise have seen. It is similar to geocaching in that you must find a hidden item. The difference is that instead of using a gps to find the letterbox (instead of a cache), you have clues to find it. The activity combines treasure hunting, clue solving and personal stamp artistry. Read more in the links provided here.
Atlas Quest International Letterboxing
dmoz directory on letterboxing
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