Monnow Bridge Pont Trefynwy Bridge in Wales View of the bridge looking north Coordinates 51°48′32″N 2°43′12″W﻿ / ﻿51.8090°N 2.7200°W﻿ / 51.8090; -2.7200Coordinates: 51°48′32″N 2°43′12″W﻿ / ﻿51.8090°N 2.7200°W﻿ / 51.8090; -2.7200 Carries Pedestrian traffic Crosses River Monnow Locale Monmouth, Monmouthshire, Wales Characteristics Design Bridge tower Material Old Red Sandstone Total length 34.80 m (114.2 ft) Width 7.30 m (24.0 ft) No. of spans 3 Piers in water 2 History Construction start c. 1272 Listed Building – Grade I Official name Monnow Bridge and Gateway Designated 15 August 1974 Reference no.