It is, in fact, the remains of a fulacht fia, one of the most common yet persistently mysterious archaeological monument types found across Ireland. The term refers to a prehistoric cooking site, typically identified by a horseshoe-shaped mound of fire-cracked stones accumulated over repeated use. The standard interpretation is that stones were heated in a fire and then dropped into a water-filled trough to bring it to the boil, though scholars continue to debate whether these sites were used primarily for cooking, bathing, textile processing, or some combination of purposes.

The site at Tyrrelstown Little came to light in 1994 during topsoil stripping, which exposed a spread of burnt stone and charcoal-flecked soil measuring ten metres in length and six metres in width. Three flint flakes were recovered as surface finds, small worked stone fragments that hint at human activity in the area beyond the cooking site itself, though their precise relationship to the fulacht fia is unclear. The record was compiled by archaeologist Geraldine Stout. The location in boggy ground beside a stream is entirely typical of the monument type; ready access to water was essential to how these sites functioned, and low-lying, poorly drained ground has helped preserve the charcoal and heat-shattered stone that make them recognisable in the first place.

Tyrrelstown Little sits in west Dublin, an area that has seen considerable development pressure over the decades, which makes the survival and recording of sites like this all the more significant. The feature was identified during groundwork rather than targeted excavation, so what is visible above ground today, if anything remains accessible, is likely to be subtle at best: a slight discolouration of soil, perhaps a scatter of fire-cracked stones at the surface. Anyone with an interest in prehistoric landscape would do well to approach this kind of site with an eye for context, noting the proximity of the stream and the character of the surrounding ground, rather than expecting a dramatic upstanding monument.