Beneath the wheels and footfall is stonework dating to 1713, making it the oldest surviving bridge in the city, and one of the oldest three-centred bridges in Ireland.

The older, upriver section, roughly fifteen feet wide, was built in 1713 and later extended on the downriver side in 1824. Its construction is notably accomplished for the period. A three-centred arch, as opposed to a simple semicircular one, is formed from three arcs of different radii, producing a flatter, more elliptical curve that distributes load more efficiently; the technique requires careful cutting of the individual wedge-shaped stones, known as voussoirs, that form the arch ring. The 1713 section has a central arch spanning twenty-six feet, flanked by side arches of twenty-one and twenty-three feet, all three-centred, carried on two slender river piers just four feet five inches thick. As O'Keeffe and Simington noted in 1991, those piers are remarkably thin given the spans they support. The bridge is not an isolated survivor; Clark's Bridge, built upriver in 1766 with a single segmental arch spanning sixty-eight feet, was the longest such span in Ireland at the time of its construction, suggesting that Cork was something of a centre for ambitious bridge engineering in the eighteenth century.

The 1713 stonework is not immediately obvious from street level, partly because the 1824 extension altered the overall profile and partly because the bridge now sits flush within a busy road corridor. Looking at the structure from the riverbank, however, the distinction between the two phases of construction, and the shallow elegance of those original three-centred arches, becomes considerably clearer.