Ancient Doodles Around the World

This, along with Stonehenge, is another thing that I would do just to mess with people if I had a time machine.

Oh wait...

Mysterious ancient symbols found throughout the world. Source: https://t.co/vzCu3a0mYC pic.twitter.com/gJ7bJku9c2

— Cliff Pickover (@pickover) March 3, 2019

(Tip of the cap to math prof.)