For those that don't know, Geocaching is a world wide phenomena where (fairly odd) people hide "caches" (treasure boxes!) and post them on line for others to find.
Some are easy. Most are not.
I have found one under a bridge, one inside a disused shower on the beach in Brighton and one in New York.
I have found others, too!
Those that are "in" on it are cachers. Those who are not are charmingly referred to as "Muggles" (although I'm sure that's been wizarded away from somewhere else!).
It is free to do and, if like me, you have two young Things to entertain, it can give you somewhere to go and seething to do.
My count is now over 50 - and two of these I got for being part of a flash mob.