[blend of geo + cache]
A type of scavenger hunt in which participants are given the geographical coordinates of a cache of items, which they then locate using GPS navigation hence, geocacher
"Geocaching is a new Web-based fad that could have Alaskans
flying to Finland to find treasure hidden under fallen
trees. Players stash the goods -- any-thing from native art
to sunglasses -- and leave directions at
www.geocaching.com."
- Time, Oct. 2000
"..these RVers had apparently decided to get a jump on the
tourist season and be the first geocachers of the year to
make it to the sites in question."
- Neal Stephenson, REAMDE (2011)