The Crumlin Viaduct was a railway viaduct located above the village of Crumlin in South Wales, originally built to carry the Taff Vale Extension of the Newport, Abergavenny and Hereford Railway (NA&HR) across the Ebbw River.Hailed as "one of the most significant examples of technological achievement during the Industrial Revolution", in its 109 years of service until being dismantled in 1967, it remained: the least expensive bridge for its size ever constructed; the highest railway viaduct in the United Kingdom; the third highest viaduct in the world, after the aqueduct at Spoleto, Italy, and the timber viaduct in Portage, New York state.