The one at Gortknockaneroe is the most northerly of the group, a low, irregular mound of burnt stone and scorched earth measuring roughly 8.6 metres by 9.5 metres and rising no more than 20 centimetres above the surrounding terrain. It is easy to miss, and that is rather the point.

A fulacht fia, sometimes called a burnt mound, is among the most common prehistoric monuments in Ireland, yet one of the least remarked upon. The basic technology is straightforward: stones are heated in a fire, dropped into a water-filled trough, usually timber-lined, and the boiling water is used for cooking, possibly bathing, or other purposes requiring sustained heat. What accumulates over time is the discarded pile of cracked, fire-shattered stone that forms the characteristic horseshoe or kidney-shaped mound seen at sites across the country. At Gortknockaneroe, the mound sits on the north side of a drain, which hints at the original hydrology of the place, a spot where water was reliably present, which is precisely what these sites require. Two further examples lie immediately to the south-west, one almost adjacent and a third roughly 70 metres away, suggesting repeated or concurrent use of this particular patch of boggy ground over what may have been a considerable span of prehistoric time.