Geocaching is the high-tech pursuit of hiding and seeking containers, known as geocaches,
or caches, using GPS devices. There are over 1.4 million geocaches worldwide.
Geocaches come in a variety of sizes, and are usually either tupperware or ammo
boxes. They would most often contain a logbook to record geocache finds, and perhaps
several low-value, token objects.
A range of less common geocaches can also be found, such as virtual caches, where
reaching the cache location is the aim. Similarly, webcam geocaches may require
the finder to capture a photo of themselves at the cache.
Geocaching locations can be downloaded from a number of websites, mostly for free.
These downloads come in the form of GPX files, giving the location of the geocache,
along with descriptions of the cache.
Geocaches can be hunted with most handheld GPS devices - both dedicated walking
GPS devices, or mobile phones with build-in satellite navigation. These three are
good examples of dedicated walking GPS devices.