A crop circle estimated to measure about 390 feet in diameter was spotted near Devizes, England, Aug. 6 and a 60-foot-diameter was discovered in a wheat field about 15 miles away just five days later, The Mirror reported Monday.
No one has yet come forward to take credit for the circles.
Lucy Pringle, an aerial photographer and crop circle researcher, took images of the designs.
"The season started very late this year due to the cold winter and spring," she said. "Suddenly it is all happening just as most overseas visitors have left our shores. Both these circles are the largest and most elaborate so far this summer and contain interesting geometry."