Some Native American cultures built large stone circles by laying stones in a particular pattern on the ground. They are known as “medicine wheels” —the term refers to the common believe that these stone circles served as places where one meditated for spiritual healing of the soul. However, the actual purpose of these structures remain unknown.

Medicine wheels are found all over northern United States and southern Canada, but the most famous medicine wheel is located at the summit of Medicine Mountain in Bighorn National Forest, in the U.S. state of Wyoming. The Bighorn Medicine Wheel was the first such structure to be associated with the term “medicine wheel”.

Photo credit: Frank Richards/Panoramio