Geocaching is an outdoor treasure-hunting game in which the participants use a Global Positioning System (GPS) receiver or other navigational techniques to hide and seek containers (called "geocaches" or "caches") anywhere in the world. A typical cache is a small waterproof container (usually a tupperware or ammo box) containing a logbook and "treasure," usually toys or trinkets of little value.

Geocaches are currently placed in over 100 countries around the world and on all seven continents, including Antarctica.

History

Geocaching is similar to the 150-year-old game letterboxing, which uses clues and references to landmarks embedded in stories. Geocaching was imagined shortly after the removal of Selective Availability from GPS on May 1, 2000, because the improved accuracy of the system allowed for a small container to be specifically placed and located. The first documented placement of a GPS-located cache took place on May 3, 2000, by Dave Ulmer of Beavercreek, Oregon. The location was posted on the Usenet newsgroup sci.geo.satellite-nav as . By May 6, 2000, it had been found twice and logged once (by Mike Teague of Vancouver, Washington). According to Dave Ulmer's message, the original stash was a black plastic bucket buried most of the way in the ground and contained software, videos, books, food, money, and a slingshot.

Origin of the name

The activity was originally referred to as GPS stash hunt or gpsstashing. This was changed after a discussion in the gpsstash discussion group at eGroups (now Yahoo!). On May 30, 2000, Matt Stum suggested that "stash" could have negative connotations, and suggested instead "geocaching."

Geocaches

Typical cache treasures are not high in monetary value but may hold personal value to the finder. Aside from the logbook, common cache contents are unusual coins or currency, small toys, ornamental buttons, CDs, or books. Also common are objects that are moved from cache to cache, such as Travel Bugs or Geocoins, whose travels may be logged and followed online. Cachers who initially place a Travel Bug or Geocoin often assign specific goals for their trackable items. One such goal could be to pass it westward across the continent. Occasionally, higher value items are included in geocaches, normally reserved for the first to find, or "FTF", or in locations which are harder to reach.

Geocache container sizes range from containers as small as the tip of your little finger ("nanos"), to film canisters (often called "microcaches"), too small to hold anything more than a tiny paper log, to five-gallon buckets or even larger containers.