It is, in fact, the remains of a fulacht fia, a type of prehistoric cooking site found in extraordinary numbers across Ireland, and one of the more quietly remarkable categories of monument that the island preserves. The typical fulacht fia consists of a horseshoe-shaped mound of fire-cracked stone, usually surrounding a trough that would once have been lined with wood or clay. The working method, as understood from experimental archaeology, involved heating stones in a fire and dropping them into a water-filled trough until the water boiled, allowing meat to be cooked with reasonable efficiency. The shattered, heat-fractured stones were then raked aside, building up the distinctive mound over repeated use.

Fulachtaí fia, to use the Irish plural, date predominantly from the Bronze Age, roughly 1500 to 500 BC, though some examples have been recorded from earlier and later periods. They are among the most common archaeological monument types in Ireland, with many thousands recorded nationally, yet individual examples often go unnoticed precisely because their profile is so low and their material so unassuming. A crescent of dark, fragmented stone in a damp hollow does not announce itself the way a ringfort or a megalithic tomb might. The site at Cashel, Co. Mayo, is one such monument, recorded but, for now, not extensively documented in publicly available sources.