Machynlleth Bridge

Cadw's description

Summary description and reason for designation

The following provides a general description of the Scheduled Ancient Monument.

The monument consists of the remains of a bridge, dating to 1805, in the post-medieval period. The bridge spans the river Dyfi and consists of 5 segmental stone arches, all of one build, forming a total span of 64m. The width between the parapets is c.5.5m. Small pilasters are present above the cutwaters on both sides. Steel reinforcement bars have been incorporated into the structure of the bridge in the first two parapets from the south end in view of sheer weight of water during flooding. Records from the time of construction suggest that the bridge was constructed on dry land and the river then diverted to run underneath it, although there is no evidence on the ground to suggest that the course of the river has been substantially altered at this point. It may have been constructed alongside, and slightly downstream of a 17th century bridge; successive bridges are recorded here or nearby from the early 15th century onwards.

The monument is of national importance for its potential to enhance our knowledge of post-medieval construction techniques and transportation systems. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits. The structure itself may be expected to contain archaeological information concerning chronology and building techniques.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.