What survives here is a spread of burnt material measuring sixteen metres north to south and eight metres east to west, sitting on a north-facing slope in what is now tillage land. The mound itself is the giveaway: generations of repeated heating and fracturing have left behind a dark, crescent-shaped or horseshoe-shaped spread of fire-cracked stone and charcoal, the archaeological signature that has allowed these sites to be identified across Ireland in such remarkable numbers.

A fulacht fia, in the simplest terms, is the debris left by a Bronze Age cooking or heating site, typically consisting of a timber-lined trough, a hearth, and a mound of the spent stone that accumulated as hot rocks were used to boil water. The process involved heating stones in a fire and dropping them into a water-filled trough, which would bring the water rapidly to the boil. The stones shatter with repeated thermal shock and quickly become useless, building up the characteristic mound over time. Sites like this one are usually dated to the Bronze Age, roughly 1500 to 500 BC, though some may be earlier or later. The Knocknamarriff example, recorded in the Archaeological Inventory of County Cork published in 1997, occupies an unremarkable stretch of agricultural ground, which is precisely what makes it representative. The vast majority of fulachta fia were never monuments in any grand sense; they were functional places, used and abandoned, now legible only as a stain in the soil.