Britannia Tubular Bridge (part in Llanfairpwllgwyngyll Community)

The bridge piers are of rock-faced Anglesey limestone (Penmaen marble), set on a plinth, and Runcorn sandstone and brickwork. Each of the 2 central water piers is 67.5m (221ft 3ins) high from foundation on the sea bedrock, and rise in rock-faced coursed stone with battered sides to an ashlar corniced top raised on large corner blocks forming voids, originally designed to take suspension chains over rockers, on each face, all in an Egyptian Pylon style. The piers are voided, and stone lintels 6m (20ft) long span the rectangular holes for the twin tubes, with bold plat bands at the level of the top and bottom of the tubes. Each side face carries a symbolic engineering motif based on linked driving rods. The outer spans spring to similar abutment towers, flanked by sculpured lions on high plinths (q.v.). A huge figure of Britannia designed by Thompson for the centre pier was never executed. Inscribed on the approach face 'Erected Anno Domini MDCCCL Robert Stevenson Engineer'.

The modified bridge, opened in 11/6/1980, consists of braced rivetted steel section arches with 'N'-truss spandrels spanning between the earlier piers, with the roadway carried on stanchions above the railway. The side spans are in reinforced concrete.