The Chirk Railway Viaduct lies directly to the west of Chirk Aqueduct and carries the Shrewsbury to Chester railway across the Ceiriog Valley. The viaduct was built to the design of Henry Robinson, chief engineer to the Shrewsbury to Chester Railway, in 1846-1848, with Thomas Brassey the general contractor. The Shrewsbury to Chester line was initiated by Robinson, who had received his training under George Stephenson, and who recognised the need, not met by the canals, to transport materials to Wrexham and Chester. The line became part of the Great Western Railway system in 1854.

It is built of coursed squared rock-faced stone with the upper arch stage of brick faced with stone. It is approximately 260m (849ft) long, comprising 16 arches, ten forming the major span, rising 30m (100ft) above the river. The three arches at either end were first built in wood but replaced in stone in 1858. The main piers are tapered upwards to the an ashlar fascia and torus moulding on the springing line, above which there are decorative arched niches with architraves, keystones and pediments. The arches between piers have ashlar voussoirs, with a dropped keystone (Cadw listing).

Sources:
Hubbard E, Clwyd, Buildings of Wales series, 1986, p130;
Hurdsman C N, A History of the Parish of Chirk, 1996, pp149-150;
Sivewright W J, Civil Engineering Heritage, Wales and Western England, 1986.

RCAHMW, 4th September 2008