Stopped off specially yesterday to phot this little baby (whilst en route to the imperial war museum with my hairy buddy Newage) An odd one this-it is a two storey affair, although i think that the lower storey which is just an extension of the bridge parapit, was built to give it extra strength(there are no embrasures in the lower section,just an entrance.)The top section is five sided and contains six embrasures and an entrance reached by a fixed ladder on the railway side.Pillboxes near central London are definately not common and this one is definately worth pointing a few thousand pixels at !!!!The location being Putney Bridge stn on London Undergrounds District Line.