Alston Arches Viaduct. Newcastle and Carlisle Railway Company Haltwhistle-Alston Branch opened on 17 November 1852. the branch was closed on the 1 May 1976. The viaduct was restored in 2006 by the North Pennines Heritage Trust. Opened to the public as a footpath on 10 July 2006 by HRH The Duke of Gloucester KG GCVO