Burgos in Spain, and the Pont Valentré, in Cahors, France. But urban expansion, the lessening of defensive requirements, and the substantial increases in traffic and trade from the 18th century onward led to the destruction of many of what was once a common bridge type. The rarity of Monnow Bridge and Gate is reflected in its status as a potential World Heritage Site, a scheduled monument, and a Grade I listed building; its listing describing it as "an outstanding medieval fortified bridge, now unique in Britain". See also Bridge castle Explanatory notes References Sources External links Geograph photos of Monnow Bridge Bridges in Monmouthshire Stone bridges in the United Kingdom Deck arch bridges Bridges completed in the 13th century Grade I listed bridges in Wales Grade I listed buildings in Monmouthshire Scheduled monuments in Monmouthshire Buildings and structures in Monmouth, Wales Pedestrian bridges in Wales Former toll bridges in Wales