The kids these days have it easy: pick up their smartphones, click the button, and applecadabra they have a photograph which is automatically dated and geolocated to within a metre of where they are standing. When I was a young lad – alright, when I was pushing middle age – you had to be inventive if, in your dotage, you wanted to remember where you took a photograph. You had to find a convenient building with a name on and incorporate that into the photograph. What better than a timeless, solid, signal box. The only problem was, within a few years someone had come along and demolished your geotag, it had vanished like a puff of steam.