Afon Gwyrfai Bridge at Bont Newydd is a single arched bridge that was constructed to carry the Nantlle Railway over the Afon Gwyrfai. The Nantlle railway connected Caernarfon Quay (NPRN 34153) to the Nantlle Slate quarries and the Drws y Coed copper mines.

The bridge was visited by Brian Malaws of RCAHMW on 26 February 1992 and it was noted as having a span of 15.3 metres and being 6.15 metres wide at the base, but narrower at the crown, which was not accessible. The height of the arch was 4.6 metres from the springing level that was approximately one metre above the water level. The arch was made from large rusticated stone blocks that were 70 centimetres deep. Both approach embankments were visible, standing up to 4.5 metres high on the south side, although they been quarried and cut for farm access and housing estate roads.

Source:
Site notes of B.A.Malaws , RCAHMW, 26 February 1992
David Gwyn & Merfyn Williams (1996) `A Guide to the Industrial Archaeology of North West Wales?. Association for Industrial Archaeology

RCAHMW, 3 November 2011