At Cherryville in County Kildare, excavation uncovered something that looks, at first glance, like a patch of scorched rubble: a spread of fire-shattered stone and charcoal-dark soil, thirteen metres long and seven metres wide, sitting quietly beside a stream. This is a burnt mound, a type of prehistoric site found across Ireland and Britain whose precise purpose has kept archaeologists arguing for decades. The leading theory is that these mounds represent the remains of ancient cooking sites, where stones were heated in a fire and then dropped into water-filled troughs to bring the water to a boil, shattering in the process and being discarded in a growing heap. Some researchers favour other explanations, including sweat-house bathing or industrial processes, but the combination of heat-cracked stone, charcoal, and water sources is consistent wherever these sites appear.

The excavation, carried out under licence by Thaddeus C. Breen, found that the burnt spread overlay four pits. Two were modest oval cuts, roughly 1.2 metres and 0.95 metres long, and a third was a much larger, irregular pit measuring about 2.5 metres by 2 metres and nearly a metre deep. The relationship between one of the smaller oval pits and the larger one is particularly suggestive: the smaller sat at a higher level and may have drained into the larger through a gap in the wall between them, a gap that had subsequently been blocked. Eight post-holes were arranged around the larger of the two oval pits, though not at regular intervals, hinting at some kind of timber structure above or around it. The stone in the burnt spread was a mix of limestone and sandstone, in a ratio of roughly thirty to nineteen. Finds were sparse but telling: a waste flint flake and a fragment of an iron vessel, both recovered from within the pits. The flint points to activity in prehistory, while the iron fragment complicates the picture slightly, suggesting either a long period of use or later disturbance.