#4 - Geocaching starts

You are advised to read the introduction for cache #1 before attempting this cache, especially with regard to the path between #3 and #7.

On 2nd May, 2000, the US government switched off selective availability on the Global Positioning System (GPS), which meant hand-held units became much more accurate. The following day Dave Ulmer posted a message on the Usenet newsgroup sci.geo.satellite-nav.

Geocaching was born!