A singular bridge

Linda, Ian and I went for a lovely walk in the Pentlands today. We climbed White Hill to Bonaly Reservoir, and then over to Harbour Hill. From there we headed east to Capelaw, Allermuir, downhill to Swanston and home again via Smithy Cleugh.

There is an unusual bridge in the cleugh which is solidly built in sandstone, but very narrow (less than a metre wide) and going nowhere. The whole area around here was covered in gorse until last year and so the bridge would have been hidden from view. I wonder if it has anything to do with the water supply for Edinburgh? The bridge looks about the same age as the Water Works house at Torduff Reservoir.

We saw dozens of people sledging today. Can you see the cardboard sledges being carried in this blip?