Pont Maentwrog spans the Afon Dwyryd and probably dates from the late eighteenth century, possibly 1780, when the roads of Merionethshire were turnpiked. It has three elliptical arches of stone voussoirs with a string course above the arches and a low parapet wall with stone slab copings; there are triangular cutwaters with raking tops on each side. The bridge formerly carried both the A487 trunk road and A496 road but a new alignment of the former, by-passing the bridge, has relieved some of the traffic pressure. At the south end of the bridge is a toll cottage (nprn 409442) and milestone (nprn 409441).
Pont Maentwrog represents the upper extent of the Afon Dwyryd Navigation (nprn 91424).
B.A.Malaws, RCAHMW, 18 August 2009.