It measures roughly ten metres north to south, eight metres east to west, and rises to about sixty centimetres at its highest point. A smaller spread of the same burnt material lies just to the south and may be part of the same site. To most eyes it would read as nothing more than a damp, unremarkable hump in the landscape, but it is almost certainly a fulacht fia, one of the most common yet least understood monument types in the Irish countryside.

Fulachtaí fia are prehistoric cooking sites, typically Bronze Age in date, found in their thousands across Ireland. The standard interpretation is that they worked by heating stones in a fire and then dropping them into a water-filled trough, bringing the water to a boil quickly enough to cook meat. The characteristic horseshoe-shaped mound that marks these sites today is the accumulated debris of those sessions: cracked and shattered stone, discarded once it had fractured from repeated heating and cooling. They almost always appear near water, whether a stream, a spring, or boggy ground, and the location at Lackaduv fits the pattern precisely. The marshy setting and the proximity to a stream are not incidental; both would have provided the reliable water supply the process required.