Only where the stream has cut into the ground and exposed a cross-section of the mound does its true nature become apparent: a dense layer of heat-shattered stones packed into charcoal-rich soil, roughly forty centimetres deep, the unmistakable signature of a burnt mound.

Burnt mounds, known in Irish archaeology as fulachta fiadh, are among the most common prehistoric monuments in Ireland, yet they remain genuinely puzzling. The working theory is that they served as outdoor cooking sites, where stones were heated in a fire and then dropped into a water-filled trough to bring it to the boil. The discarded, cracked stones accumulated over repeated use into the characteristic D-shaped or horseshoe mounds that survive today. The example at Carrownageeragh measures approximately six to seven metres north to south and five metres east to west, modest in scale but consistent with the type. The eroding section face, where the stream gully has cut through, offers a rare unintended window into the mound's interior, with the layer of shattered stone visible at a depth of around 1.2 metres. What makes the location quietly interesting is the density of monuments in a small area: a second burnt mound of the same class lies roughly 200 metres to the south on the opposite bank of the same stream, and a rath, a type of enclosed farmstead typically dating to the early medieval period, sits about 200 metres to the east. Whether these features are connected in time or simply reflect centuries of people making use of a convenient watercourse is a question the landscape does not answer easily.