These are fulachtaí fia, a term referring to prehistoric cooking sites, typically consisting of a trough, a hearth, and a mound of fire-cracked stone. The usual method involved heating stones in a fire and dropping them into a water-filled trough until the water boiled, after which meat could be cooked. What survives at Knockahorrea is the burnt stone spoil, the waste material that accumulated over repeated use and was raked or thrown aside to form the characteristic horseshoe-shaped or irregular mounds seen at sites like this across Munster.

The five mounds here range considerably in size, from the smallest at roughly 3.5 metres by 4.9 metres to the largest at approximately 6.9 metres by 5.3 metres. The spread of burnt material across an area of 17 metres north to south and 14 metres east to west is notable, and it has been suggested that what appears as five distinct oval or circular mounds may in fact be the badly eroded remains of a single, larger original mound. The site does not stand in isolation. A second fulacht fia lies approximately 80 metres to the east, and a third around 110 metres to the south-east, a clustering that points to repeated or prolonged activity in this part of the stream valley, where a reliable water source would have made such sites practical. The immediate landscape, bounded by a field fence and a stream to the north, has likely changed little in the broad outlines that would have made this spot attractive in the first place.