Though it's not obvious from this picture, the two rectangular plantations on the distant hillside have been planted with different coloured foliage to read "ER". Perhaps a jubilee thing, though the woods are marked on Ordnance Survey maps so it may not have been the 2012 jubilee. Worth checking out on aerial photo sites. [Update: they were planted in 2002 for the Golden Jubilee, per another photo of the same thing.]
Uploaded to Geograph by Dave Dunford on 22 July 2012
Photo © Dave Dunford, 22 July 2012. Licensed for reuse under this Creative Commons licence