Crossing the Glenborbry River in the townland of Killacolla, sometimes recorded under the name Barker, it is a single-span, segmental-arched structure, meaning its arch describes a shallow arc rather than a full semicircle, a form common in Irish road bridges from the eighteenth and nineteenth centuries. What makes it quietly interesting is not the bridge you can see, but the one you cannot, and the one that was not yet there at all.

When a contemporary drawing captured the 1600 siege of nearby Glin Castle, no bridge appears at this crossing point on the Glenborbry. Yet by the time of the Down Survey, the mid-seventeenth-century mapping project commissioned under Cromwellian administration to record forfeited Irish lands, a bridge had appeared here. That structure is almost certainly the one Samuel Lewis described in 1837 as an "ancient bridge" in his Topographical Dictionary of Ireland, a work that catalogued the built and natural features of the country parish by parish. The bridge visible today has the appearance of a mid-nineteenth-century replacement, suggesting the crossing Lewis noted had by then become worn or structurally inadequate and was rebuilt, as so many rural Irish bridges were during the decades following the Famine when road improvement schemes were common.

The bridge sits in a rural part of west County Limerick, not far from the Shannon estuary and the territory historically associated with the Knights of Glin. There is nothing particularly dramatic about the approach; it is a working agricultural road rather than a heritage trail. Those who do make their way here should look at the curve of the arch from the riverbank if access allows, where the quality of the stonework and the proportions of the span are most legible. The Glenborbry is a small river, and the crossing modest in scale, which makes the long documentary thread running back through Lewis, the Down Survey, and the silence of that 1600 siege drawing all the more worth pausing over.