Mystery of 200ft crop circle within yards of Stonehenge...

Who built Stonehenge has long been the subject of debate among scholars.

But now the ancient site has offered up another conundrum - in the form of a giant crop circle.

This impressive 200ft design appeared within sight of the ancient monument yesterday.

And as ever the debate will rise as to who is responsible.

Some believe they are manmade, others that they are caused by earth's magnetic field. And there are a number who are convinced they are the work of extra-terrestrials

The ancient site is widely considered the most important prehistoric monument in Britain and is proving to be a hot spot for the phenomena this season. More + pictures...

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