The tourist office listed here the existing hiding places (not exhaustive list) and couldn't be held responsible.
Geocaching is a mix of a high-tech treasure hunt and an orienteering course – and now you can get involved in the Pays de Voltaire! Armed with your smartphone, answer the questions and solve the puzzles. This unique experience is open to everyone, offering an unusual way to discover the Pays de Voltaire.
It's a great way for adults and kids alike to relax. You'll need to sharpen your sense of observation and find the "geocaches" (boxes containing items that you can exchange and a logbook). Then simply leave a comment, place your own object in the box, and put it back again. Once you get back home, you then share your discovery with the community.
Information and inscription: www.geocaching.com
This is the original geocache type consisting of, at minimum, a container and a log book or logsheet, as well as items for trade. The coordinates listed on the traditional cache page provide the geocache’s exact location.
The golden rule is: "if you take an object from the box, leave something of equal or greater value and write about your find in the logbook."