It measures roughly 7.6 metres north to south and 7.4 metres east to west, which makes it a reasonably substantial example of one of Ireland's most common and most puzzling monument types: the fulacht fia.

A fulacht fia, sometimes called a burnt mound, is the residue of a Bronze Age cooking or industrial site. The typical method involved heating stones in a fire, then dropping them into a trough of water to bring it rapidly to the boil. The stones shatter and discolour with repeated heating and cooling, and over time the discarded fragments accumulate into a low, often horseshoe-shaped mound of charcoal-rich soil and broken rock. Thousands of these sites survive across Ireland, making them the most numerous prehistoric monument class in the country, yet they remain only partially understood. The exact purposes they served, whether primarily for cooking meat, processing hides, brewing, or bathing, is still debated. The example at Monee fits the classic profile: the characteristic semicircular spread, the burnt material, the modest but unmistakable footprint left by repeated use over what may have been generations.