4. The human butterfly crop circle – the largest known crop circle with dimensions of 1738×1476 feet, this crop circle is believed to be a work of the aliens as it is humanly not possible to carve out such n enormous figure on the field just by using rope and wood plank
5. The Wiltshire crop circle which got created in 2007 in reportedly 7 minutes time had 160 circles which required the flattening of almost 2 acres of wheat crops.
6. The “409 Spiral Circles” crop circle is believed to be done by aliens as such massive formation would require a lot of man-days to get completed.
7. The mystery of the Nazca Lines in Peru is also seen in the “Nazca line Hummingbird” crop circle which is believed to be an alien artwork.
8. Flower crop circle in Italy is also not believed to be a work of humans owing to its high precision and complex geometric patterns.
9. The Chilabolton Arecibo message crop circle that was spotted in August 2001 had two different images, both made of many small pixels. One of them represented a face and the other one resembled a radio signal that was sent out by SETI (The Search for Extraterrestrial Intelligence) way back in 1974.
10. The most mysterious of all crop circles is the Alien face crop circle that has a clear image of the face of an alien along with a binary coded message made by flattening the crop. The binary coded message reads “Beware the bearers of false gifts and promises. Much pain but still time. There is good out there. We oppose deception. Conduit Closing”.