On the north face, the inscription reads 'Leader Bridge / Richard Griffith / Engineers'; on the south, 'W IV Rex 1834', placing the structure firmly in the reign of William IV and giving it a date precise enough to situate it within a very particular moment in Irish infrastructure history. That combination of named engineer, named patron, and regnal date is not something you encounter every day on a rural river crossing in north Cork.

The bridge carries a road across the River Allow at a point roughly 120 metres north of its confluence with the Blackwater, and its construction is notably careful. The main fabric is random ashlar, meaning stones of varying sizes laid without uniform courses, but the details are dressed: the three segmental arches are fitted with raised limestone voussoirs, the wedge-shaped stones that lock an arch together, here given chamfered edges that catch the light at an angle. A string course runs above the arches, and an overhanging ashlar coping tops the parapet. On the upstream, northern side, two bluntly pointed cutwaters project from the piers; these triangular projections divide the current and deflect debris, reducing pressure on the bridge during high water. The engineer named on the plaque, Richard Griffith, was one of the most consequential figures in nineteenth-century Irish public works, known later for the General Valuation of Ireland, the land survey that produced what became known as Griffith's Valuation. His involvement here places this modest river crossing within a broader programme of state-directed road and bridge building in the pre-Famine decades. The bridge is noted as similar in design and detail to Duncannon Bridge elsewhere in County Cork, suggesting a consistent approach across the works attributed to his office.