What it actually represents is a fulacht fia, one of the most common prehistoric monument types in Ireland and yet one of the least understood. These horseshoe or crescent-shaped mounds are the accumulated debris of repeated fire-setting and water-heating episodes, most likely dating to the Bronze Age. The process involved heating stones in a fire until they were near-fracturing point, then dropping them into a water-filled trough to bring it rapidly to the boil. Over many uses, the thermally shattered stones were raked out and piled to the sides, eventually forming the distinctive mound that survives today.

The example at Liscottle measures roughly twelve metres east to west and around ten metres north to south, rising to about 0.4 metres at its western edge. It sits over a layer of dark peaty soil and is composed, as is typical of the type, of a dense concentration of shattered stones packed into black soil. The southern edge of the mound shows a hollow approximately 1.8 metres wide, which may mark the original position of the cooking or heating trough, the functional centre of the whole operation. The mound is most clearly defined along its southern to north-western arc, while the north-eastern and eastern edges become less distinct, fading into the surrounding ground. Some ridging running roughly north to south across the surface appears to be the product of relatively recent disturbance, perhaps agricultural activity, rather than anything prehistoric.