Started officially in 2000, coinciding (but not by coincidence) with a more-accurate GPS network. Long before what would now be considered “smart” devices (Palm Pilot, Handspring Visor, etc) had any sort of GPS abilities. You had to have, or know someone who owned, a handheld GPS device.
https://en.m.wikipedia.org/wiki/Geocaching
Started officially in 2000, coinciding (but not by coincidence) with a more-accurate GPS network. Long before what would now be considered “smart” devices (Palm Pilot, Handspring Visor, etc) had any sort of GPS abilities. You had to have, or know someone who owned, a handheld GPS device.