Looking at Google Earth I found this circular mark in a field near Winterbourne Bassett in 2003, and I think I can just see traces of it on the 2006 photograph as well.
Pastscape doesn't seem to have anything marked here, so I thought it might be the shadow left after a crop circle. But looking at 2002 and 2003 crop circle photographs, ie http://www.temporarytemples.co.uk/imagelibrary/2003.html , nothing seems to come close.
There is one in 2009 in the same field - http://www.flickr.com/photos/richard_bradshaw/3816697405/ which is obviously too late for this.
Anyone got any ideas?
Here is the interactive Google map locating it.
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