Only one car was allowed on the bridge at one time, not only because it was narrow but because it was weak. It was a tight squeeze going through the posts, not much room for error [good job I wasn’t driving he he] On the England/Scotland border.
This one is at a lovely place called Cragside.
This photo was taken from a bridge at Berwick-upon-Tweed. The two bridges above this are also at Berwick-upon-Tweed.