When a northeast-to-southwest forest drain was dug through recently planted ground, it sliced through a layer of heat-shattered stones and charcoal-darkened soil sitting just fifteen to twenty centimetres below the surface. That layer runs for roughly six metres along the drain's sides and base, and it is the signature of a burnt mound, a type of prehistoric site found widely across Ireland and Britain whose precise purpose has long puzzled archaeologists.

Burnt mounds typically consist of fire-cracked stones accumulated around a hearth and a trough, the stones having been heated and then plunged into water to raise its temperature. They are generally associated with the Bronze Age, though some examples span a broader range of dates. What the water was used for, whether cooking, bathing, industrial processes, or some combination of these, remains a matter of debate. What makes the Moanroe site particularly curious is the density of related features in a very small area. One confirmed burnt mound lies approximately forty-five metres to the north-northwest, and a second possible example sits roughly forty-five metres to the north-northeast. Three such sites clustered within a hundred metres of one another suggests this corner of Cork was, at some point, a place of repeated or sustained activity rather than a single isolated episode.