Monnow Bridge in Monmouth, Wales, is the only remaining mediæval fortified river bridge in Great Britain with its gate tower still standing in place. It crosses the River Monnow (Welsh: Afon Mynwy) just above its confluence with the River Wye.
In March 2005, it was closed to traffic as a new road bridge opened up in Monmouth, before that this bridge was the main way in to Monmouth.
The bridge was built late in the 13th century, being completed in 1272. In 1297 Edward I provided a murage grant in favour of Monmouth, permitting and enabling the townspeople to build the medieval town walls and gates for defence and protection. By 1315, this work was still incomplete or was in need of repair, since the original authority granted in 1297 was renewed on June 1, 1315.
The gatehouse, called Monnow Gate, which gives Monnow Bridge its remarkable and noteworthy appearance, was added to the bridge in the 14th century. Neither Monmouth town nor its castle was attacked during the rebellion of Owain Glyndwr, despite Abergavenny’s being burned down and Grosmont’s suffering the same fate during the uprising.
A new road bridge over the Monnow was opened on March 15, 2004, allowing the old bridge to become pedestrianised.