It is not especially dramatic to look at, overgrown with ferns and slowly sinking into the wet peat, but its shape gives it away: a horseshoe curve of burnt material, roughly fourteen metres north to south and just over twelve metres east to west, rising to about one and a half metres at its highest point. The opening faces east, and inside it sits a small stone-lined trough, just over a metre square and only fifteen centimetres deep, its defining stones still protruding above the saturated soil.

This is a fulacht fia, a class of monument found in enormous numbers across Ireland, most of them dating to the Bronze Age, roughly 1500 to 500 BC. The standard interpretation is that they functioned as outdoor cooking sites: stones were heated in a fire, then dropped into a water-filled trough, bringing the water rapidly to the boil. The characteristic horseshoe or kidney-shaped mound that surrounds the trough is the accumulated debris of cracked and fire-shattered stone, discarded after each use. The Coolies example sits on level ground at the confluence of two streams, a location that makes practical sense; a reliable water supply would have been essential to the whole operation. What makes the site quietly interesting is its company: a narrow grass path separates this mound from a second probable fulacht fia just two metres to the east, suggesting the spot was returned to more than once, or that both features were in use at the same time.