This crop circle appeared near Barbury Castle in June 2008. The design has a striking mathematical precision...

The racheting arcs starting at the center and proceeding outward express Pi as increments of a circle divided into tenths, or 36 degrees. If you proceed outward from the center, the multiples of 1/10 of a rotation (including the small circle as a decimal) are 3.141592654...

 

π = 3.141592654...

Various other photos from the crop circle site are shown below.

 

Crop circle formation first detected June 1, 2008