Geocaching is an outdoor recreational activity, in which participants use navigational techniques to hide and seek containers, called “caches”, anywhere in the world. A typical cache is a small waterproof container containing a logbook where the geocacher enters the date they found it and signs it with their established code name.

After signing the log, the cache must be placed back exactly where the person found it. Larger containers such as plastic storage container typically contain items for trading-toys or trinkets of little financial value, although sometimes very sentimental.

Geocaching shares many aspects with benchmarking, trigpointing, orienteering, treasure-hunting, letterboxing, and waymarking.