As explained on the title page, geocaching is one of our main hobbies, and it involves wandering about the countryside following a signal from a GPS receiver until you either find the cache you're searching for, or give up in disgust. Luckily we have only had to do the latter on a couple of occasions :-)
Cache containers can vary widely, although the most common is probably the lunch-box type tupperware container. We have found large and small tupperware boxes, screw-top beakers, metal ammo boxes, 35mm film canisters and even the tiny metal tubes usually used to attach address details to pet collars.
The types of location where a cache may be found varies even more. They can be found in town, village or countryside, sometimes in the most ingenious hiding place. They may tucked under a tree root, hiding in a sign-post or, on one memorable occasion, underwater, attached to the mooring rope of a canal narrowboat. Although "hidden at the base of an ivy-covered tree" does seem to have become something of a geocaching cliche, you really never know quite what you're going to find.
I think the main reason we enjoy geocaching so much is that it gives you a reason to get out-and-about, visiting places you may never have come across otherwise, and getting plenty of exercise into the bargain. We generally prefer trying to find two or three caches on a trip, combining them if possible into a circular walk (ideally with a pub somewhere en-route!) - the main purpose is the hike, the fresh-air, the scenery and the feeling of achievement, rather than the caches themselves.
This page contains a set of statistics for all the Caches we have visited, for sad people like me who like that sort of thing! You an also access a page showing a sort of "diary" of our various caching trips. At the point I started writing it, we had already visited over 100 caches, so the early ones are limited as to detail, but hopefully later ones will have much more information. I hope reading about our experiences will tempt others into trying this fun and healthy hobby, and that they get as much out of it as we do.