The Coolcour bridge once carried road traffic over the Sullane River in mid Cork, but when the Lee Valley Hydro-electric Scheme flooded the valley in the mid-twentieth century, it went under along with the surrounding landscape. The replacement bridge stands a short distance to the west; the original, according to scholars O'Keeffe and Simington, lies approximately fifty metres to its east, invisible now except in memory and record.

What makes the Coolcour bridge more than a footnote is the company it keeps, architecturally speaking. It was built in the style associated with the bridges at Glanworth in north Cork and at Kilcrea, both of which are regarded as fine examples of Irish medieval or early post-medieval stone bridge construction, typically featuring multiple rounded arches springing from sturdy cut-stone piers. An old sketch confirms the seven-arch arrangement at Coolcour, suggesting a structure of some considerable length and ambition for a rural crossing. The bridge was already established enough to be clearly marked on Herman Moll's map of 1714, one of the more detailed cartographic records of Ireland produced in the early eighteenth century, which places its construction somewhere before that date, though the precise period remains unrecorded.