Yet beneath the drumlin-softened landscape of County Monaghan, preparatory groundwork uncovered what turned out to be a fulacht fia, one of the most common yet persistently puzzling monument types in Irish archaeology. A fulacht fia is, in essence, a prehistoric cooking or processing site, typically identified by a spread of fire-cracked stone and charcoal-stained earth accumulated around a trough or pit where water was heated by dropping in stones made red-hot in a fire. They occur in their thousands across Ireland, and their sheer frequency only makes the questions they raise more interesting.

The site at Drumcaw, designated Drumcaw 1 during excavation, presented as a single spread of burnt stone within a charcoal-enriched clay matrix, roughly 6.3 metres east to west and 6 metres north to south, lying no more than 0.22 metres deep at its thickest point. Beneath that spread, three distinct hollows had been cut into the subsoil, the largest measuring 3 metres by 1.4 metres, the others somewhat smaller, each relatively shallow at around 0.15 to 0.18 metres deep. These hollows are consistent with the kind of working troughs associated with fulacht fia activity. A sample of alder charcoal taken from the most easterly of the three pits, which had later been cut through by a north-south drain, was radiocarbon dated to 3888 plus or minus 30 BP, placing activity here somewhere between 2470 and 2288 cal. BC. That date puts the site firmly in the Early Bronze Age, a period when this type of site was in widespread use across the island. The low-lying position among drumlins, those smooth elongated hills left behind by retreating glaciers, would have made the spot naturally damp and likely well-watered, precisely the kind of location where fulacht fia activity tends to cluster.