The example recorded at Killow in County Clare belongs to a class of monument that archaeologists call fulacht fiadh, a term loosely meaning cooking pit of the wild. The typical form is a low, crescent-shaped mound of fire-cracked stone and charred material, built up over repeated use beside a water source. Water was heated by dropping stones, first made red-hot in a fire, directly into a trough or pit. The stones shattered with use and were discarded to the side, gradually forming the distinctive mound shape that still survives in boggy ground across Ireland today.

Most burnt mounds date to the Bronze Age, roughly between 1800 and 800 BC, though some were in use earlier or later. They are found in low-lying, often waterlogged ground, which is precisely the kind of terrain that tends to preserve organic material and resist later agricultural disturbance. What they were actually used for remains a matter of some debate. Cooking is the traditional explanation, but experimental archaeology and ongoing research have raised the possibility that some served as sweat houses, textile-processing sites, or brewing facilities. The honest answer is that the evidence points in several directions at once, and the Killow mound, like so many of its kind, keeps its purpose to itself.