It is not. The mound, measuring eighteen metres north to south and twelve metres east to west, rising to just thirty-five centimetres at its highest point, is a fulacht fia, one of the most common yet least understood monument types in the Irish landscape. The term, loosely meaning "cooking place of the deer" in Old Irish, refers to the characteristic horseshoe or oval spreads of shattered burnt stone that accumulate over time around a trough or pit used for heating water. Stones were placed in a fire until intensely hot, then dropped into a water-filled trough to bring it to a boil. Repeated heating and sudden cooling causes the stones to fracture and become useless, so they are discarded to the side, gradually building up the mound that survives today.

Thousands of fulachtaí fia have been recorded across Ireland, the majority dating to the Bronze Age, roughly 2000 to 500 BC, though some were in use earlier or later. They are almost invariably found close to water, whether a stream, a spring, or a boggy hollow, and Coolbane fits the pattern precisely, sitting just metres from a stream in what is now pasture. What purpose they served beyond the obvious one of cooking is still debated; some researchers have proposed uses ranging from textile processing to communal bathing. Two shallow hollows towards the southern end of the Coolbane mound, apparently dug in relatively recent times, hint at the curiosity the site has attracted locally, though their precise origin is unrecorded.