Geocaching is a unique and fun outdoor activity. Geocachers use GPS systems or mobile apps to find containers, called caches or geocaches, all over the planet.
Most geocaches are small containers which contain a log of everyone who has found that particular cache before. Traditionally geochachers take a small item from a given cache and leave one of their own.
Check out this video of cachers Jeff and Evan out geocaching for some more info.
photo: screensshot from chilproductions1 via youtube.com