The links above will lead you to the German version of this website !
Geocaching some kind of treasure hunt with internet und GPS.Someone hide a cache and publish the corresponding informations on the internet.Anyone can get those informations and search with them the cache. Requires an account on www.geocaching.com (Free). There are about 2 Millons active Caches on earth, even on the space station ISS. (don't ask me how to get it)
There are different kind of caches: Mysterys, adventure, special places etc.
Cache Types (not complete)
Traditional Cache: The cache is hidden at the published coordinates.
Multi-Cache: Some kind of scavanger hunt with two or more stations.
Mystery-Cache: First you have to solve a mystery to get the coordinates.
Earth-Caches: Nothing is hidden, there are special rules to log an Earth-Cache.