1. Letterboxing is an outdoor hobby which began on the moors of Dartmoor, England. Letterboxers hide a small weatherproof box in publicly accessible places and post clues to its location. Clues to letterboxes on Darmoor are traditionally distributed in print format in the Dartmoor 100 Club's regularly-updated catalogue; in the U.S., clues are published on the Letterboxing North America and other web sites. Interest in letterboxing in the United States is generally considered to have started with a feature article in the April 1998 Smithsonian Magazine.
Further information:
Anne Swinscow has written several popular guide books on Dartmoor Letterboxing, e.g. Dartmoor Letterboxes ISBN 0950911429
The Letterboxer's Companion by Randy Hall (ISBN 0762727942) was published in 2003 and focuses on letterboxing in North America
