some mushrooms grow naturally in arcs or circles called fairy rings that can be found in forests and woodlands. there are several myths explaining this phenomenon that have circulated for centuries. European folklore explains the rings as gateways into elfin kingdoms, or places where elves gather and dance (the mushrooms being used as stools for small creatures). according to common myth, the ring appears when a fairy, pixie, or elf is present, and will disappear without trace in a matter of days; but if an observer waits for the elf to return to the ring, he or she may be able to capture it.
gateway to another world or not, it’s a pretty cool natural phenomenon. interesting how random things in nature organize themselves into not-so-random order.