It rises only 0.35 metres above the surrounding grass, measures roughly 7.2 metres north to south and 8.2 metres east to west, and opens northward with a gap of about six metres across. That horseshoe outline, and the dark, burnt material packed within it, mark it out as a fulacht fia, one of the most common yet persistently mysterious monument types in the Irish landscape.

Fulachtaí fia (the plural form) are Bronze Age cooking sites, found in their thousands across Ireland, typically beside water sources. The standard interpretation is that stones were heated in a fire, then dropped into a water-filled trough to bring it to the boil, and the cracked, fire-shattered fragments were discarded to either side, gradually building up the characteristic horseshoe mound over repeated use. The proximity of the Garryadeen example to a stream fits this pattern precisely; running water would have kept the trough supplied. Some researchers have proposed alternative uses, including textile processing or sweat-house bathing, though the cooking explanation remains the most widely accepted. The burnt stone itself is what survives most visibly, giving these sites their other common name, burnt mounds. Thousands have been recorded across Ireland, yet individual examples like this one, sitting quietly in ordinary farmland, rarely attract much attention.