Happy 20th birthday, geocaching! – Official Blog

May 2, 2000: Or as geocachers call it, Blue Switch Day. This is the day the United States government removed selective availability on civilian GPS receivers, therefore enabling the accuracy of GPS technology to improve tenfold.

May 3, 2000: The first “geocache” is placed. However, the first geocache was not called a geocache at all, but a “GPS Stash.” Although the original geocache is no longer in place, there is a plaque marking its location and a physical container with a logbook for visitors to sign. Watch a video of Lackeys visiting the plaque!

Source: Happy 20th birthday, geocaching! – Official Blog