Glossary of Terms



Cache In Trash Out - When out geo-caching, take a bag with you and pick up trash along the way!



Pronounced "cash" - In geo-caching it is a hidden container filled with a log book and pencil/pen, and possibly prizes. In the past caches were often used by explorers, miners, etc. to hide foodstuffs and other items for emergency purposes. People still hide caches of supplies today for similar reasons.
Geo-caching comes from the terms "geo" and "cache" to explain the sport.


Cache In Trash Out Event

Cache In Trash Out is an activity intimately tied to geocaching. While on a cache hunt, participants collect litter along the trails and properly dispose of it. Cache In Trash Out Events are much larger clean-up events that involve and benefit the larger community.


Confluence Bagging

A related sport in which players attempt to be the first to find and report a confluence point, or point at which a line of latitude and longitude cross. At these confluence points the form is to take photographs of the cardinal points, of your GPS showing the exact location, and write a report of your surroundings and submit it to the Degree Confluence Project at All the points on the UK mainland have been logged, although many people still go to visit previously logged points. Geo-caches are sometimes located nearby.


Event Cache

Occasionally, local geocachers and geocaching organizations designate a time and location to meet and discuss geocaching. After the event the caches are “archived” or listed as no longer active.



First To Find. Usually found in the forums or written in the online or physical log books.



A non geo-cacher. Based on "Muggle" from the Harry Potter series, which is a non magical person. Usually this term is used after a non geo-cacher looks puzzled at a geo-cacher making circles with their GPS receiver, or when a non-geo-cacher accidentally finds a cache. Geo-muggles are mostly harmless.



GPS stands for Global Positioning System. It is a system of satellites that work with a GPS receiver to determine your location on the planet.



Slang for a GPS receiver. Equipment to receive GPS signals for use in navigation.



A hitchhiker is an item that is placed in a cache, and has instructions to travel to other caches. Sometimes they have logbooks attached so you can log their travels. A Travel Bug is an example of a hitchhiker.



Letterboxing is similar to Geo-caching, but you use a series of clues to find a container. Once you find the container (or letterbox), you take a carved stamp from the box and stamp your personal logbook. You then take your carved stamp and stamp the letterbox's log book. Letterbox Hybrid.

 A letterbox is another form of treasure hunting using clues instead of coordinates. In some cases, however, a letterbox has coordinates, and the owner has made it a letterbox and a geocache.


Locationless Cache

These are in effect the opposite of a traditional cache and are a similar idea to Waymarks. Instead of being given a set of coordinates with which to find a hidden container you are asked to locate a specific object as a sort of scavenger hunt and then log its coordinates to prove that you found it. Examples are listed on


Mega-Event Cache

A Mega-Event cache is similar to an Event Cache but it is much larger. In order to qualify as a Mega Event, the event cache must be attended by 500+ people. Typically, Mega Events are annual events and attract geocachers from all over the world.


Multi-Cache (offset Cache)

A multi-cache ("multiple") involves two or more locations, the final location being a physical container. There are many variations, but most multi-caches have a hint to find the second cache, and the second cache has hints to the third, and so on. An offset cache (where you go to a location and get hints to the actual cache) is considered a multi-cache. The clues to each cache are sometimes organised into themes such as the signs of the Zodiac, or chemical elements. Some of the clues can be extremely challenging and educational.


Mystery or puzzle caches

This form of cache can involve complicated puzzles you will first need to solve to determine the coordinates. The only commonality of this cache type is that the coordinates listed are not of the actual cache location but a general reference point, such as a nearby parking location. More elaborate versions involving several locations are known as Multi Caches (see above). Due to the increasing creativity of geocaching this becomes the staging ground for new and unique challenges, such as coordinates hidden in a sudoku puzzle Other caches might involve “Da Vinci Code” style clues, answers to general knowledge questions, crossword clues or mathematical puzzles.


Puzzle cache

This is a series of caches in which each has a clue to the location of a final secret cache.



A spoiler is information that can give details away and ruin the experience of something. For example, telling someone the end of a movie before they see it. In geo-caching, a spoiler gives away details of a cache location and can ruin the experience of the hunt.


Themed Caches

People often give their caches a witty or appropriate name, a local example is “Way out West” on the tip of the Llŷn Peninsula. Cache makers are sometimes inspired to base a cache or series of caches at a site of historical significance. Multi caches (see above) are often themed.



Thanks for the cache!



Thanks for the hunt!



Took Nothing. Left Nothing. Usually found in cache logbooks for folks that enjoy the thrill of the hunt more than the material contents of the cache.



Took Nothing. Left Nothing. Signed Logbook / Took Nothing. Signed Logbook.


Traditional Cache

This is the original cache type consisting, at a bare minimum, a container and a log book. Normally you'll find a tupperware container, ammo box, or bucket filled with goodies, or smaller container ("micro cache") too small to contain items except for a log book. The coordinates listed on the traditional cache page is the exact location for the cache.

The general rule of thumb is, "If you take an item, leave an item, and write in the logbook." Some caches are themed, so make sure to read the description before going on a hunt.


Travel Bug

A Travel Bug is a hitchhiker.


Virtual (cache)

Adapted from "Virtual Reality," virtual means "nothing there." So a virtual cache means there is no cache container. It's the location that is the cache itself. Nothing is normally traded, except photos and experiences.



This is a related activity that evolved from Virtual Caches in which participants log interesting locations and post them on a separate website There is no physical cache at the location but the site itself is interesting enough to warrant a visit, local examples include historical monuments such as Harlech castle, and significant trig points with good views of surrounding countryside.


Webcam Cache

This is another virtual cache type that makes use of existing web cameras placed by individuals or agencies to monitor various areas like parks. The idea is to get yourself in front of the camera to log your visit. The challenging part, however, it that you need to call a friend to look up the web site that displays the camera shot. You will need to have them to save the picture to log the cache. If you’re a tech-head you could use your wireless modem and save the image yourself on your laptop. Examples are found on


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