Welwyn Railway Viaduct, Bessemer Road, Welwyn Garden City, Hertfordshire
This railway viaduct was built for the Great Northern Railway. It was built in 1848-50 by Sir William Cubitt and Joseph Cubitt. It has 40 arches. It cost £69,397 and is made of 13 million bricks. It was opened on the 7th of August 1850.