It sits in the crown of the third arch from the eastern end of this sandstone bridge, invisible to drivers passing over it, and its name alone signals that this is not a straightforwardly ordinary piece of infrastructure. The bridge as a whole is an object lesson in how river crossings accumulate history in layers, each phase of construction quietly readable in the stonework if you know where to look.

The structure crosses the Sullane on a roughly east-west axis and was built in at least three distinct phases, giving it an overall width of 8.2 metres. The oldest portion appears to be the southern side, about 5 metres wide, identifiable by its roughly cut voussoirs, the wedge-shaped stones that form the curved faces of the arches, and its pointed breakwaters, the projecting piers that deflect the river's current away from the bridge's supports. Two of those breakwaters rise all the way to parapet level, where they become semicircular in profile; the eastern one carries a recess in the parapet wall containing a memorial to An tAthair Peadar Ua Laoghaire, the Cork-born priest and writer celebrated as a pioneer of modern Irish-language prose. The bridge was later widened northward by 3.2 metres, the new section matching the semicircular arch style of the original. Then came the flood of 1853, which damaged the structure and appears to have prompted the insertion of two wide segmental arches at the western end, their cut limestone voussoirs and prominent keystones distinguishing them clearly from the rougher sandstone work on the older sections. Traces of semicircular overflow arches survive on the western bank, remnants of an earlier attempt to manage the Sullane's periodic anger.

The bridge rewards a slow look from the riverbank rather than from the road above. The shift from rough-cut sandstone to dressed limestone marks the boundary between the pre-flood and post-flood phases of construction, and the breakwaters rising into the parapet give the southern elevation an unusual verticality. The Hangman's Hole, for its part, remains covered and unexplained in any surviving documentary record, its name preserved only in local memory.