Twenty-six countries reported approximately 10,000 crop circles in the last third of the 20th century; 90% of those were located in southern England. Many of the formations appearing in that area are positioned near ancient monuments, such as Stonehenge.
According to one study, nearly half of all circles found in the UK in 2003 were located within a 15 km (9.3 miles) radius of Avebury. Archaeological remains can cause crop marks in the fields, in the shapes of circles and squares, but they do not appear overnight and they are always in the same places every year.
Crop circles were first noticed in the 1970's when simple circles began appearing in the English countryside. The number and complexity of the circles increased dramatically, reaching a peak in the 1980's and 1990's when increasingly elaborate huge circles were produced, including those illustrating complex mathematical equations and known illustrations. The precision and detail is amazing.
While there are countless theories, the only known, proven cause of crop circles is humans. Their origin remained a mystery until September 1991, when two men confessed that they had created the patterns for decades as a prank to make people think UFOs had landed. They never claimed to have made all the circles — many were copycat pranks done by others — but their hoax launched the crop circle phenomena
Most crop circle researchers admit that the vast majority of crop circles are created by hoaxers. But, they claim, there's a remaining tiny percentage that they can't explain. The real problem is that (despite unproven claims by a few researchers that stalks found inside "real" crop circles show unusual characteristics), there is no reliable scientific way to distinguish "real" crop circles from man-made ones. There are many theories, besides human intervention, about what creates crop circles, from aliens to mysterious wind patterns, but they all lack one important element: good evidence. Perhaps one day a mysterious, unknown source will be discovered for crop circles, but until then perhaps they are best thought of as collective public art. They do capture ones imagination and are fascinating to contemplate.
The designs are thought to be created by someone stomping down the stalks with a flat board. Wheat, barley, or rape(canola oil) are the most common crops they are found in but can also appear in rye, maize,
and a number of others.
That sounds like it could get pretty tiring after awhile, stomping out one of those really huge intricate patterns. Size can vary from circles of just a foot or so across to designs covering many hundreds of feet
Crop circles have intrigued me ever since I saw the
first pictures of them because they always seem so
precise and symmetric and totally out of place. I consider whoever or
whatever creates them to be unique, and a little strange, that
so much effort would be spent perfecting an intricate design
in various fields that nature or
harvesting would eventually erase. It boggles my
mind to think that just two men could create any of these
immense designs, in only the moons light, overnight.