What lies beneath is a fulacht fia, a type of prehistoric cooking site found in considerable numbers across Ireland, typically Bronze Age in date. The name, roughly translatable from Irish as "cooking place of the deer," refers to a distinctive method of heating water: stones were fired in a hearth, then dropped into a water-filled trough until the contents boiled. The cracked and heat-shattered stones were discarded in a mound nearby, and it is these accumulations of fire-reddened and blackened stone that survive in the landscape, sometimes for thousands of years.

At Pluckanes, the burnt material extends for some eighteen metres along a drain running parallel to the stream, and spreads roughly five metres west from the drain into the field. The site sits on the western bank of the stream, a typical location: fulachta fia are almost always found close to water, which was both a practical necessity for the cooking process and, perhaps, a factor in site selection for reasons we can only speculate about. The concentration and spread of the material here gives a sense of sustained or repeated use rather than a single episode, though the archaeology of the subsurface would need excavation to confirm anything more specific about the site's history.