You're just walking to your car after leaving the store...or your favorite restaurant ...or you are taking a nature walk with your beloved Dog and you spot something unusual.
It's a rock someone has painted or decorated and hidden in the open for others to find.
You curiously yet cautiously retrieve the rock hoping to unlock it's mystery.
Typically there will be further salutations and maybe instructions on how how to handle your mysterious find.
The Rock will probably read something like "post my pic to Facebook or IG instagram, re-hide or keep" along with clues as to the Local Rock & Hide Group it came from. These groups have members that help monitor associated Social Media accounts to really make it a lot more fun and akin to geo-caching.
My local group uses 719 ROCKS after our main phone area code. Other informal groups do as well or perhaps the use name of the city. If there isn't a local group, anyone may certainly start one, no strings attached, no financial dues involved.
You can simply search Facebook for the related groups and search Instagram using # hashtag keywords. A general Web search using keywords like "painted hidden rocks" and variations of, should show you all the clues you need to find or start a group in your area.
As a side note....I have also seen this basic concept tweaked for self promotion of websites, businesses and local events.
Sincerely, Yvon ~ Mid Life Hustle