At roughly eight metres across and just forty centimetres high, it would be easy to walk past without a second thought. But this is a burnt mound, a class of prehistoric site found widely across Ireland and generally understood to be the remains of ancient cooking or industrial activity. The typical interpretation involves heating stones in a fire, plunging them into a water-filled trough to bring it to the boil, and then discarding the cracked, heat-shattered stones nearby. Over time, those discarded stones accumulate into exactly the kind of kidney-shaped or circular mound visible here.

What makes this particular example quietly interesting is its relationship to a neighbouring site. The mound at Lissooleen is described as lying to the west of another burnt mound of almost identical dimensions, the two sitting close enough together to suggest either contemporaneous use or repeated activity in the same small area over time. Such pairings are not unheard of in the archaeological record, but they invite speculation about the nature and scale of whatever was happening here, whether a single community returned to this spot across generations, or whether two separate episodes of use happened to leave near-identical traces. The site was recorded by Michael Connolly during a survey of the Lee Valley area carried out in 1996 and 1997.