They appear as low, inconspicuous spreads of fire-cracked stone and dark, charcoal-rich soil, and for decades their purpose divided opinion. The leading theory now holds that they were cooking sites, where stones were heated in a fire and then dropped into a water-filled trough to bring it to the boil, a method sometimes called a fulacht fiadh. They cluster particularly around wetland margins and watercourses, suggesting that access to water was central to whatever was happening at them.

The example at Ballynapark in County Wicklow came to light not through targeted investigation but through the kind of accidental discovery that road construction so often produces. It was excavated by archaeologist Ellen O'Carroll as part of the N11 road improvement scheme, one of many interventions along that corridor that opened windows into the landscape's prehistoric past. Such rescue excavations, carried out ahead of development, frequently recover sites that would otherwise remain invisible and unrecorded. The N11 project generated a considerable body of new archaeological data from across County Wicklow, and the Ballynapark burnt mound forms part of that wider picture.