Good, fun article …

Fairy-rings-in-moss-in-Iceland

these rings in Iceland are ancient …

Do you dare enter a fairy ring? The mythical mushroom portals of the supernatural

For thousands of years, the sudden appearance of a ring of mushrooms was a sure sign of otherworldly presences. These rings would seemingly appear overnight, or travel from one location to another, with no clear rhyme or reason. Warnings of the dark forces that must create these abnormalities were passed down between generations, and the folklore of fairy rings was established.

These fairy rings (fairy circles, elf circles or pixie rings) are a naturally occurring phenomenon. A fungi creates a ring or arc shape within the soil, affecting the grass in the area, and grows up through the greenery forming a circle of mushrooms. These rings—a lovely surprise and good luck to some, or a dark omen and nasty lawn problem to others—can spread from a very few inches or feet to 164 feet (50 meters) or more. The ring found in Belfort, France, is thought to be the largest ring ever found. It is approximately 2,000 feet (600 meters) in diameter, and an astonishing 700 years old.

via Do you dare enter a fairy ring? The mythical mushroom portals of the supernatural | Ancient Origins.