The mound stretches roughly 38 metres east to west and 24 metres north to south, making it a notably large example of its kind, and the depression at its northern side still holds water today, much as it would have thousands of years ago.

A fulacht fia, the term used across Irish archaeology for these burnt mound sites, is generally understood to have functioned as an outdoor cooking place, probably dating to the Bronze Age. The typical method involved heating stones in a fire, dropping them into a water-filled trough or pit to bring it rapidly to the boil, and then cooking meat submerged in the heated water. The stones, shattered and spent by repeated thermal shock, were raked aside after each use, and over time that discarded material accumulated into the distinctive horseshoe or kidney shape that survives so reliably in the landscape. The depression at the centre, often still damp or boggy, marks where the trough once sat. At Lerrig, the waterlogged hollow on the northern side is consistent with this pattern. The site was recorded by Danagher in 1983 and later included in C. Toal's North Kerry Archaeological Survey, published in 1995.

Fulachtaí fia are found in their thousands across Ireland, particularly in low-lying or boggy ground where water was close to the surface, and Kerry has a strong concentration of them. What makes individual sites worth lingering over is less any dramatic visible feature than the ordinariness of the evidence: a curved mound, a wet patch, and the implication of repeated communal activity carried out in the same spot over generations.