Crop circles definition : Crop circles are areas of cereal or similar crops that have been systematically flattened to form various geometric patterns. The phenomenon itself only entered the public imagination in its current form after the notable appearances in England in the late 1970s. Various scientific and pseudo-scientific explanations were put forward to explain the phenomenon, which soon spread around the world.First logical question : Why the H*ll alien do that for?
In 1991, more than a decade after the phenomena began, two men, Doug Bower and Dave Chorley, revealed that they had been making crop circles in England since 1978 using planks, rope, hats and wire as their only tools. Many other people around the world are also openly making crop circles. Although the commonly accepted view today is that crop circles are a man-made phenomenon, paranormal explanations, often including UFOs, are still popular.In paranormal circles the study of the crop circle phenomena is called Cerealogy. Cerealogists commonly refer to these designs as agriglyphs or landscape art.
Crop circles are found in fields, over tree-tops, and in ice and snow. They are mostly often found in wheat or corn fields, but have also been found in oat, rape (canola), and barley. They are a world wide phenomena, highlighted in England.

No one knows how far back in history they go. Allegedly, the earliest recorded crop circle is depicted in this 1647 woodcut called the Mowing-Devil.