This backwards S made out of Vesica-like eclipses in young wheat looked about two days old when I flew over it yesterday (June 14th).  It’s on top of the hill close to the Westbury White Horse in a field which is adjacent to a big chalk mine (easy to spot on the Ordnance map).

 

 Unfortunately it was late in the day and very overcast when I flew, so I had to apply so much contrast in Photoshop that the colour looks artificial.  This is sort of what it would look like if there had been sun.