Crop Circles are geometric patterns that appear mysteriously in crop fields. The crop is not cut, but is usually laid flat and most often swirled into an attractive floor pattern. Most patterns appear in cereal crops such as wheat and barley, but circles have been known to occur (in lesser numbers) in oilseed rape, maize, linseed, grass and even borage - to name a few.
The crop circles do seem to have an affinity for ancient sites. Many circles appear close to stone circles, barrows, earthworks and other landmarks. Stonehenge and Avebury have played host to many crop circles over the years.