Chelfham Viaduct is a railway viaduct built in 1896-7 to carry the Lynton and Barnstaple Railway (L&B) across the Stoke Rivers valley.
Designed by L&B engineer, F. W. Chanter, and containing over a quarter of a million Marland bricks, its eight arches - each 42 feet wide and 70 feet high - meaning that the 400-foot long viaduct is the largest narrow gauge railway structure in England.
After the L&B closed in 1935, the rest of the trackbed, buildings and land from the line was sold at auction in 1938. The viaduct, however, was not sold.
It is probable that such a redundant structure would normally have been dismantled, either then, or shortly afterwards during the war, as happened to the smaller viaduct at Lancey Brook, which was destroyed as a demolition training exercise by the Army. However, a school and other buildings at its base made it uneconomical to dismantle, so it remained in Southern Railway ownership, passing to British Railways on the nationalisation of the railways in Britain in 1948, and eventually BRB (Residuary) Ltd, formally a wholly owned subsidiary of the Strategic Rail Authority (now Network Rail).
In 2000, the viaduct was extensively restored, including the fitting of a waterproof membrane to the deck, improvements to rainwater drainage, and restoration of the parapets, leaving the structure once again ready to carry rail transport. The extra work beyond merely preserving the structure was paid for by the L&B Project – which owns the nearby station – as part of long-term plans to reopen this part of the line to regular passenger services.
The viaduct was classified as a Grade II listed structure on 25 February 1965.
Sources of Information
-  Wikipedia