A motorway bypass is not where you would expect to find evidence of prehistoric cooking, yet that is precisely what turned up near Mayfield in County Kildare in 1998, when routine monitoring of topsoil-stripping exposed the remains of a fulacht fia, one of the most common yet still somewhat puzzling monument types in the Irish archaeological landscape. A fulacht fia is broadly understood to have been an outdoor cooking site, typically consisting of a water-filled trough into which fire-heated stones were dropped to bring the water to boiling point. The stones, cracked and blackened by repeated heating, were piled nearby into a distinctive mound, which is usually how these sites are first recognised from the surface.

This particular site came to light during drainage work connected to the Monasterevin-Kildare Motorway Scheme on the N7, in the area of the proposed Mayfield Interchange. Excavation directed by Breandán Ó Ríordáin uncovered a burnt spread of roughly thirty metres square and between ten and fifteen centimetres deep. Stake-holes, charcoal, and a small quantity of burnt limestone were among the features recorded across this area. The centrepiece of the site was a pit or trough retaining a wood lining fifty to eighty millimetres thick along roughly half its interior, a detail that points to some care in its construction. Five bone fragments were recovered from the fill of the pit, three of them charred, which is consistent with the processing of animal carcasses. The evidence suggested at least three separate phases of use, though the shallowness of the surviving stratigraphy, the layered deposits that archaeologists read as a sequence of activity, implies the site was active only over a relatively short period rather than across generations.