But the remains uncovered at Ballynabarny tell a precise, if still partly mysterious, story about how people used this waterside spot in prehistoric times. What was found here is a fulacht fia, a type of ancient cooking or processing site found widely across Ireland, typically comprising a horseshoe-shaped mound of burnt stone beside a water source and a trough in which water could be heated by dropping in fire-heated stones.

The site came to light during archaeological testing ahead of the construction of the M11 Motorway, when two distinct areas of burnt mound material were identified, separated by a palaeo-channel, an ancient buried watercourse. The eastern mound, which extended beneath an existing road bank, consisted of a single compact layer of broken and burnt stone measuring roughly thirteen metres by nine and a half metres and no more than thirty centimetres deep. Beneath it lay an oval trough, just under two metres across and sixty-five centimetres deep, with steep sides, a flat base that sloped gently westward, and fifteen stake-holes concentrated along its inner edges. Small fragments of wood were recovered from those stake-holes, suggesting the trough may once have been timber-lined. Immediately to the east of the trough, excavators found a fire-spot where stones would have been heated before being plunged into water. The fills of the trough recorded the sequence of use clearly: sandy silt mixed with heat-shattered stone and charcoal at the base, covered by natural clay, then darker silts with more fire-cracked stones, all sealed beneath the spread of the mound itself. No artefacts of any kind were recovered, which is not unusual for sites of this type; fulachtaí fia rarely yield objects, offering instead a record of repeated, practical activity rather than personal or ritual deposit. The mound material had also worked its way into the alluvial deposits of the adjacent palaeo-channel, suggesting the site sat in a low, wet, water-margin landscape, precisely the kind of setting these features consistently favour.