[1] The bridge is a series of five elliptical arches of high-quality carved limestone masonry with a two-arch culvert to the east.

[1][3] Its graceful profile, architectural design value, and civil engineering heritage endow it with national significance.

[1] Colles was the owner of a marble works and an inventor of machinery for sawing, boring, and polishing limestone.

[11] Smith designed an almost-true copy of the Bridge of Tiberius (Italian: Ponte di Augusto e Tiberio) in Rimini, Italy, as described by Andrea Palladio in I quattro libri dell'architettura (The Four Books of Architecture) (1570).

[4] At the centre of medieval Irish kingdom Osraige, Kilkenny grew from a monastic settlement—now St Canice's Cathedral on the hill above the bridge—to a thriving Norman merchant town in the Middle Ages.

[6][7][8] Three important roads , including from Old Leighlin and Rosconnail (south of Ballyragget), forded the Rivers Nore and Bregagh.

[15] Later the area was converted to a mill pond associated with the Augustinian Priory of St Johns and a new bridge was needed.

[9] One arch of the former bridge spans the Greensbridge mill‐race to the east; four or five of its central pier abutments are visible in low water.

[26] Colles is credited as the inventor of machinery for sawing, boring and polishing limestone using water mills; tasks that had previously been performed by hand.

[11] A weir on the river provided water to drive reciprocating cross-cut steel band saws using sand as an abrasive, to cut the larger blocks.

[26] The River Nore was used to transport large blocks from the quarry by means of horse-drawn floats and/or barges.

[27] As part of the Kilkenny Flood Relief Scheme, an archaeological examination of the late medieval bridge was undertaken.

[16] It ran along the eastern bank of the River Nore from an inlet at Friar's Inch, under Noremount, and re-entered below Green's Bridge.