What distinguishes it is its form: three semi-circular arches rising in a gentle hump-backed profile, the kind of quietly purposeful stone engineering that once defined rural river crossings across Ireland but is now far less common than it once was.

Semi-circular arch construction, sometimes called the Roman arch, distributes weight outward and downward through the curve of each arch into the piers and abutments below, giving bridges of this type considerable durability. The hump-backed profile, rather than a flat deck, is a natural consequence of that geometry, the roadway following the line of the arches beneath it. The Ardcahan bridge carries all three arches in this form over the Bandon river, which drains a substantial portion of west Cork before reaching the sea at Kinsale harbour. Beyond its structural details, the documentary record for this particular crossing is sparse, and its precise construction date is not established.