What is geocaching? Definition from Wikipedia: Geocaching is an outdoor activity in which the participants use a Global Positioning System (GPS) receiver to seek containers (called "geocaches" or "caches") anywhere in the world. A typical cache is a small waterproof container (usually a tupperware container or ammo box) containing a logbook. Larger containers can also contain items for trading, usually toys or trinkets of little value. Geocaching is most often described as a "game of high-tech hide and seek". Geocaches are currently placed in over 100 countries around the world and on all seven continents, including Antarctica. After 10 years of activity there are over 1 million active geocaches.