The bridge carries a minor road over the private padarn Railway at the point where it emerges from a deep cutting. The railway was built 1841-3 to carry slate from the Dinorwic Quarries to Port Dinorwic, otherwise Y Felinheli. The bridge is built from local (?) rubblestone with an arch ring of slate blocks. The iron gate at the north-west side of the arch is identical to others along the railway, and was probably made at the Dinorwic Quarry workshops at Gilfach Ddu.
W J Crompton, RCAHMW, 28 October 2009.