It records a foundation stone, names Paul Horgan Esq. as the man behind the project, and gives the year 1831. That kind of documentary precision is relatively rare on rural Irish bridges of the period, where the builders and patrons often go entirely unacknowledged.

The bridge at Bawnmore is 7.5 metres wide and built with three segmental arches, meaning each arch describes a shallow curve rather than a full semicircle, a form well suited to carrying road traffic smoothly over a modest river. The voussoirs, the wedge-shaped stones that lock an arch together, are roughly dressed rather than finely cut, giving the structure a workmanlike solidity rather than any pretension to elegance. Low pointed breakwaters project upstream to divide the current and protect the piers from debris and flood pressure. A string course, a narrow horizontal band of masonry, runs across the face of the bridge above the arches, providing a clean visual line that ties the composition together. The designer named on the plaque is N. M. Fitzgerald, whose hand is otherwise not widely documented in the popular record but whose name, preserved in stone above the river, at least survives the anonymity that claimed so many of his contemporaries.