Geograph - photograph every grid square

This shot records my first glimpse of this unlikely structure. I knew nothing of its existence when I set off along a Forestry Commission track, starting at an entrance marked 'Dick Focks Common'. For a moment I thought I'd found a two-dimensional folly (lost here in the woods?) or something left over from location filming.

I scrambled up the bank only to find that if there had ever been a track going over the bridge it was now completely overgrown. The other puzzle was the narrow path that went underneath, approaching in a long narrow trench. One possibility I considered was that there may have been a narrow-gauge railway here - like one I'd seen near Hascombe: Link

Had I known more of the history of the area I'd have recognised this structure as one of the so-called Lovelace bridges - devised by William King, first Lord Lovelace, as part of a system for extracting timber. Ten bridges survive. The narrow passage beneath the bridge is in fact a bridleway - wagons loaded with logs went over the top.

The system has been documented for Geograph by Colin Smith, who also describes a trail put together by the Horsley Countryside Preservation Society: Link Plaques have been attached to a number of bridges, though not to this one (Briary Hill West) and I have to say that suits me, as I prefer to puzzle out the possibilities for myself!