It is, to the untrained eye, barely a feature at all; just a slight irregularity in the ground. But it represents a type of site found in great numbers across Ireland, a fulacht fia, which is the term for an ancient cooking or processing site, typically identified by its characteristic horseshoe-shaped mound of heat-shattered stone, accumulated over repeated use. The stones would have been heated in a fire and dropped into a water-filled trough to bring it to the boil, a method that works with surprising efficiency. Most fulachtaí fia date to the Bronze Age, roughly 1500 to 500 BC, though some were used into the early medieval period.

What gives the Liskillea example a small additional point of interest is its appearance on the Ordnance Survey six-inch map produced in 1940, where it is clearly marked on the western side of a hachured oval mound. Hachuring on older OS maps indicates a raised or sloped earthwork, suggesting that the burnt spread sits beside a low mound that was already distinct enough to warrant notation by the surveyors of that period. The marshy ground around it is characteristic: fulachtaí fia are very often found close to water sources or in low-lying, wet terrain, which would have made the constant supply of water for the trough easy to manage.