Llanelltyd Bridge is a stone construction which carried the former A470 trunk road over the Afon Mawddach; it has five elliptical arches and triangular cutwaters and is thought to date to the second quarter of the eighteenth century. According to Williams ('Cymer Abbey' in Archaeologia Cambrensis 130 (1981), pp36-58), an earlier bridge was mentioned in the later seventeenth century; certainly the crossing would have been an important one for general trade and for the monks of nearby Cymer Abbey (nprn 95420) and there are references to a bridge being in existence near the abbey in 1400. A postcard of 1906 shows a timber and stone weir on the western or downstream side of the bridge, presumably this was to prevent scouring of the piers. Increasing traffic and the narrowness of the bridge prompted the erection of a Bailey bridge on the eastern side but this was removed when a new concrete bridge was constructed in the 1980s to carry the road on a new alignment some 150m to the west. The old bridge no longer carries motor traffic but is in use as a footbridge.
B.A.Malaws, RCAHMW, 18 August 2009.