I came across an old postcard recently, which shows a northbound train crossing Monsal Dale Viaduct (actually the correct name is Headstone Viaduct) c 1908:-
My photo below is the scene as it is now with the railway being part of a footpath across the viaduct.
Oh what could have been if in the the 1950’s and 60’s we had been more forward looking and not closed many of our railways! By the way check how the trees have grown by comparing the two photos.
Check out the Wikipedia page at:-
The photos are amongst my Flickr shots at:-