Bridge Over Troubled Water
The Welwyn Viaduct, also called Digswell Viaduct, carries the East Coast Line Railway over the River Mimram. Designed by William Cubbit, it was originally opened by Queen Victoria, 6 August 1850 who was said to be so frightened of the height she refused to travel across the viaduct.
The viaduct is around 1,560ft (475m) long and comprises forty arches of 30ft (9.1m) span, and is 100ft (30m) high.
More photographs by Bill Martin can be found on Flickr.