At Lisnamuck in County Longford, a fulacht fia, essentially a Bronze Age cooking site in which water was heated by dropping fire-cracked stones into a trough, lay buried and largely invisible until construction work forced it into the open. The mound left behind by this activity measured sixteen metres long, eleven and a half metres wide, and nearly half a metre deep, composed of charcoal-rich clay and the kind of shattered, heat-stressed stone that accumulates when rocks are repeatedly superheated and plunged into cold water.

The site came to light during an archaeological excavation in 2003, carried out in advance of a large-scale commercial development. Beneath a large pit at the western edge of the mound, excavators found the trough itself, a rectangular basin measuring roughly two metres by one and a half metres, with a flat bottom and a stake-hole at each corner. The stakes would likely have supported a timber lining, a common feature of such troughs, which helped keep the structure watertight. What makes Lisnamuck particularly notable is that this site did not sit alone. Two further fulachtaí fia were identified within eighty metres, one to the south-east and one to the north, and a related burnt mound lay just thirty metres to the south-east. The clustering of so many similar features in such a small area suggests sustained, repeated use of this particular patch of ground over a considerable span of time, though the excavation report by Ó Maoldúin and Keeley, published in 2006, does not specify dates for individual episodes of activity.