It is not. The mound measures eighteen metres long, thirteen metres wide, and rises just 1.3 metres at its highest point, and it is composed almost entirely of burnt material, the accumulated debris of repeated, prehistoric firings. A shallow central depression sits at its core, and the stream that prompted the whole enterprise still flows through the south-eastern quadrant of the site.

This is a fulacht fia, a type of monument found in the hundreds across Ireland, typically dating to the Bronze Age, roughly 1500 to 500 BC. The basic principle involves heating stones in a fire until they are extremely hot, then dropping them into a water-filled trough to bring it rapidly to a boil. The stones crack and shatter with the thermal shock, and over time the discarded fragments accumulate into the characteristic horseshoe-shaped or oval mound of blackened, fire-cracked stone that survives today. The proximity to a reliable water source, in this case the stream at Clearagh, was not incidental; it was the whole point. Whether these sites were used primarily for cooking, for bathing, for textile processing, or for some combination of purposes remains a matter of ongoing discussion among archaeologists, but their association with water and heat is consistent across thousands of examples. The one at Clearagh, sitting in its marshy hollow with the stream still threading past, preserves that relationship exactly as it was set up, perhaps three thousand years ago.