You only need a GPS to type in the coordinates to be a geocacher.
The treasures or the “caches” are often placed at special historical locations. They are in a waterprof box with a log book, a pencil and various small treasures.
Once the treasure is found, you write a small greeting in the log book for the owner and subsequent visitors. You can exchange one of the treasures with a new one. Afterwards, you can register your finding at the geocaching website and share your experiences with other enthusiastic geocachers.