Discovered and recorded in February 1997, the structure consists of roundwood trunks roughly twenty centimetres in diameter, laid across a longitudinal substructure and connected using lap joints and mortises, a joinery technique in which one timber is notched to receive another. The ends of the trunks are crudely cut across, giving the whole thing a functional, unfinished character. Whether it served as a small pier, a jetty, or some form of river crossing is not definitively known, but its position near a drainage sluice close to Bunratty suggests it once played a practical role in managing movement along this tidal stretch of river.

What gives the structure a more intriguing dimension is a passage in the fourteenth-century Irish chronicle the Caithréim Toirdealbhaigh, a text that records the campaigns and deeds of the O Brien dynasty of Thomond. According to that source, Toirdelbach O Briain built a plank bridge at Bunratty that crossed the sea-channel to the opposite shore, specifically to block ships from reaching the castle. The castle in question was Bunratty Castle, which controlled a strategically important river crossing and estuary. The precise location of O Briain's bridge has never been established, but the wooden structure in the saltmarsh lies approximately two hundred and fifty metres downriver from the castle site, close enough that a connection between the two cannot be ruled out. If it is the same structure, or even a later successor built on the same spot, then what appears to be a modest arrangement of rotting timber may carry the trace of a medieval military decision.