Thanks PU, it was indeed a great day to be out and about with a camera. The photo was originally designed to be for a "negative space" entry, but I think the clouds are probably too dominant for that?
@Peter Black In my view, there's no negative space at all in this great image. It's really two subjects, the wall and the clouds, both of which (I think) take up positive space, because they vie equally for the viewer's attention. Negative space is not compelling to the eye and as such allows the viewer to see the main subject without clutter from it's surrounding.