Geocaches (also called just "caches") are the key playing pieces in the sport of geocaching. The object of geocaching is to find these caches, which vary widely in shape, size, and appearance. Some are are placed in obvious locations, while others are hidden in maddeningly obscure ways.
In the most fundamental sense, a geocache will consist of a container placed at a location of interest. The coordinates of the location are published online, enabling other geocachers to navigate to the location their GPS receivers. What makes a location interesting can vary wildly from cache to cache. At many geocache locations, the surrounding area has some attractive feature, be it a bit of local history or simply a gorgeous view. Sometimes, however, the sole draw to the geocache's hiding place is the fact that there is a geocache there.
Inside a Geocache
With only a few exceptions, a geocache contains some form of log book or log sheet. Those who find the cache should note their visit on the log. Smaller caches may have log sheets with room for only the date and the geocacher's name, but larger caches usually have log books with room for additional comments.
Many geocaches also contain trade items (or "swag"). Those who find the cache are free to trade for these items. If you take trade items from the cache, then you should leave something of equal or greater value in exchange. Typical trade items include toys, memorabilia, coupons, and signature items.
Caches may also contain hitchhikers. Hitchhikers are items that travel from cache to cache. The most common are travel bugs and geocoins, which are marked with unique tracking numbers so their travels can be tracked on the Geocaching.com website. While geocachers may keep trade items as their own, hitchhikers should not be kept, and should be moved to another cache.