Overgrown and unassuming, it is composed largely of burnt and fire-cracked stone, the accumulated debris of prehistoric cooking. A stream runs to the north.

This is a fulacht fia, a type of ancient cooking site found in great numbers across Ireland, particularly in low-lying, waterlogged ground close to running water. The typical arrangement involved heating stones in a fire, then dropping them into a water-filled trough to bring the water to a boil, used for cooking meat. The cracked, heat-shattered stones were discarded into a pile after use, and over many centuries that pile became the characteristic horseshoe-shaped mound we see today. The majority of fulachta fia date to the Bronze Age, roughly 1500 to 500 BC, though some examples span a wider period. The site at Rathaneague fits the pattern closely: the marshy ground retains water naturally, the nearby stream would have supplied it reliably, and the mound itself preserves the blackened, fragmented stone that is the signature of repeated high-temperature use.