The structure at Castleroberts was not simply built from quarried material; it was assembled, in large part, from the dismantled fabric of a medieval church and castle that once stood roughly 330 metres to the east. The bridge is, in a literal sense, a recycled monument.

The demolition of those older structures appears to have taken place somewhere around 1785 to 1795. Writing in 1865, the antiquarian Lord Dunraven recorded the account plainly: the ruins of the Castleroberts church, along with part of the old castle, were pulled down to provide building material for the river crossing. The Ordnance Survey, compiling its notes on the area in 1840, described the finished bridge as consisting of eight arches and noted a construction date of 1795. It was a practical decision, common enough in an era when a ruined structure was more useful as a quarry than as a relic, but it means that worked stones from two medieval buildings, the church recorded in the monuments register as LI021-132 and the castle as LI021-037, are almost certainly embedded somewhere in the bridge's piers and spandrels.

The bridge itself crosses the Maigue and can be approached from the surrounding road network in south County Limerick. For anyone with an interest in medieval fabric, the thing to look for is precisely what cannot be definitively identified: cut stone that seems slightly out of keeping with a late eighteenth-century build, or blocks whose proportions suggest an earlier hand. No detailed survey of which specific fragments survive in the structure appears to have been published, so the bridge rewards quiet scrutiny rather than a checklist. The site is modest and largely unremarked, which is part of what makes it worth a second glance.