There is no mound to see, no earthwork to trace, nothing to pause the eye of a passing walker. Yet that discolouration marks the remnant of a fulacht fia, a type of prehistoric cooking site found in enormous numbers across Ireland, typically consisting of a trough, a hearth, and a mound of shattered stone, cracked by the repeated process of heating rocks and dropping them into water to bring it to the boil.

The site at Coolbane is thought to be one of three such features once noted in the same general area on land belonging to a B. Purdon. All three were recorded by a researcher named Bowman in 1934, in what appears to have been a local survey of archaeological features in the district. Fulachta fiadh are usually dated to the Bronze Age, though some have produced evidence of use across a much longer span. They tend to cluster near water sources, and their sheer frequency across the Irish landscape, tens of thousands have been identified nationally, suggests they were a routine feature of prehistoric life rather than anything ceremonial or exceptional. The Coolbane example, reduced now to a subsurface stain in cultivated ground, fits a familiar pattern of survival: once the mound is levelled by ploughing, the burnt spread is often all that remains to indicate the site ever existed.