A single span arched bridge without any apparent purpose, spanning an insignificant drain flowing into the Glaslyn a few metres away. It is built without parapet of evenly graded stones each about 0.4m long carefully keyed to form an elliptical arch about 4.5m long and 1.1m above the bed of the drain. A modification to the width is noticeable on the underside - a break in masonry dividing the bridge one third/two thirds approximately. This bridge is locally referred to as the Roman bridge, a name also given confusingly in some 19th century sources to Pont Aberglaslyn nearby. A likely explanation is that the bridge is medieval in origin. It almost certainly predates the building of the cob at Porthmadog. Its function is lost now the river is no longer tidal but presumably it had a use when the area was riddled with tidal channels - the silted up drain perhaps being one of these. It could conceivably be the visible survivor of a more extensive bridge, perhaps even one crossing the Glaslyn itself. However this is difficult to determine without further exploration. A rough track now follows the river bank, but peters out at the bridge. 5m above O.D.
John Latham RCAHMW