Geocaching is a game where you go on a treasure hunt. People hide containers with objects and post the coordinates (latitude and longitude) of where they hid the containers online. You use a device like a smartphone or a GPS to get the coordinates and then you go to the location to look for the container. You can log when you find the container and take something from the container (like a toy) and leave something in the container (like a toy). It's a fun way to explore nature and discover hidden places.