What looks like a natural hillock is actually a spread of burnt material, the telltale signature of a fulacht fia, a type of prehistoric cooking site found in great numbers across Ireland. The typical fulacht fia consisted of a trough, usually timber-lined or stone-lined and filled with water, into which fire-heated stones were dropped to bring the water to a boil. The broken, heat-shattered stones were then discarded nearby, accumulating over time into the characteristic horseshoe-shaped mound that archaeologists now recognise across the Irish landscape.

What makes this particular site in Killeagh worth pausing over is not the mound itself but its company. Within a radius of roughly 250 metres, at least three further fulachta fiadh sit in the same general area. One lies about 60 metres to the south-southeast, another around 90 metres in the same direction, and a fourth some 250 metres to the southeast. Whether they were used simultaneously or represent repeated activity at the same favoured location over a long period is not clear, but the clustering is striking. Sites of this kind tend to favour stream sides, where a reliable water supply was essential, and here the westward-facing position beside a watercourse fits exactly that pattern. Such concentrations of fulachta fiadh are not unheard of in Cork and elsewhere, but finding four so close together in one pasture draws attention to whatever it was about this particular spot, perhaps the stream, perhaps the local topography, that made it worth returning to again and again.