It measures roughly fourteen metres east to west and twelve metres north to south, and it has been sitting there, slowly churning through the plough zone, for somewhere between three and four thousand years. This is a burnt mound, known in Irish archaeology as a fulacht fiadh, one of the most common yet least explained monument types in the Irish landscape.

Burnt mounds typically date to the Bronze Age, and the basic process behind them is well understood even if their precise purpose is debated. Stones were heated in a fire and then dropped into a water-filled trough to bring the water rapidly to a boil. The thermal shock shattered the stones, rendering them useless for reheating, so they were discarded to one side. Over generations of repeated use, the crescent or kidney-shaped mound of spent, heat-shattered stone grew around the trough. The charcoal-enriched soil at Cloncouse is consistent with this process, the residue of those repeated firings mixed into the ground over long use. The proximity to a stream would have been essential, providing a reliable water source to fill and refill the trough. Whether the site was used for cooking, bathing, textile processing, or some combination of these remains an open question that applies to burnt mounds across Ireland generally, and Cloncouse offers no particular evidence to settle it one way or another.