Fairy rings/circle are a naturally occurring ring/arc of mushrooms. People used to believe that fairies used to gather around and dance in a circle and leave trampled, dead grass. They day after the dance, mushrooms would spring up.
Now we know better and have a less magical scientific explanation.
"Psyche in the Temple of Love" (1882) (detail) by Sir Edward John Poynter (1836-1919).
Enya - Only Time
Château de la Mothe-Chandeniers, France.
John William Godward,A Congenial Task (Detail) 1915.