Ribblehead Viaduct is a grade II listed structure near Hawes in the Yorkshire Dales. A few years ago, I visited Carlisle via the Settle to Carlisle Railway, which goes over Ribblehead Viaduct. Sitting on the train, you don't get much of a view of the viaduct so it was nice to stop off and see it a few weeks back when I was in the Dales.
You can see the viaduct from the road. It's only a 5-minute walk from the car park and I got to see a couple of trains crossing the viaduct.