The spread measures roughly 12 metres east to west and 7 metres north to south, a modest footprint that belies what was, in its time, a functioning installation for heating large quantities of water or steam.

Burnt mounds, known in Irish archaeology by the term fulacht fiadh, are among the most common prehistoric monument types in Ireland, and Cork has an exceptional concentration of them. They typically consist of a trough dug into the ground, a hearth nearby, and a growing mound of fire-cracked stone discarded after repeated heating and quenching. The exact purpose remains debated: cooking, bathing, textile processing, and brewing have all been proposed with varying degrees of experimental support. What survives at Coolymurraghue is characteristic of the type, the charcoal-enriched soil a residue of sustained, repeated burning over what may have been generations of use. A second possible example of the same monument type lies approximately 50 metres to the north-east, which is not unusual; burnt mounds frequently appear in loose clusters, suggesting that particular locations, often near water sources, were returned to repeatedly.