Ok, time for a few bridges from the south-west of England, all in the counties of Devon or Cornwall, or in some cases both.
clapper bridge spanning the East Dart near Princetown. It's believed to date to the 13th century, and is a Grade II* Listed Building and Scheduled Ancient Monument.
The granite slabs each span about 3m, and are reported to weigh up to 8 tons each.
I'd have preferred to have seen the bridge with fewer visitors, it seems almost uncouth for something so primitive to be so well-used.
As a designer, I wonder why it is acceptable to have no handrail on an ancient monument but one would be demanded on an equivalent bridge built today. Surely the risk of falling off is the same in either case? Does protection of heritage have more importance than the risk of injury, or should we simply recognise that the risk of injury is so low as to be an irrelevance, whether many centuries ago or today?