To read an excellent article about the largest structure ever built for a Light Railway line in the UK and to see great photos go to

http://www.semgonline.com/structures/struct_44.html

The Cannington Viaduct served the Lyme Regis Branch Line

and is situated at the edge of Uplyme, right on the Devon/Dorset border

between Combe Pyne and Lyme Regis. There is no public access to the viaduct but it is visable in the vicinity of Cannington Farm Campsite DT7 3SW.