Machynlleth road bridge was built in 1533, repaired in 1681 and rebuilt in 1805. It is a 5-arch rubble bridge, having round arches with arch rings, voussoirs, thin pilaster buttresses between each arch and very low pointed cutwaters. Modern reinforcements to the west end cutting across the end arches on both sides create a more gentle curve in the main road. The bridge was the scene of a civil war battle.

Reference: Cadw listed buildings database.
See the article by Leslie Leigh on 'Pont ar Ddyfi' in the Journal of the Merioneth Historical and record Society, vol. XIV: 4 (2005), pp. 319-26.
R.F.Suggett, RCAHMW, December 2005.