They appear as low, kidney-shaped mounds of fire-cracked stone and charcoal-flecked earth, typically found close to a water source, and the one recorded at Ballyleaan in County Clare is a local example of this widespread but often overlooked type of site.

Burnt mounds, known in Irish archaeology as fulachtaí fia, date most commonly to the Bronze Age, roughly 1500 to 500 BC, though some are earlier or later. The prevailing interpretation is that they functioned as outdoor cooking or processing sites. The method involved heating stones in a fire, dropping them into a water-filled trough to bring it rapidly to the boil, and repeating the process until the stones fractured and became useless. The discarded, heat-shattered stone accumulated over time into the characteristic mound. Some researchers have proposed alternative uses, including hide-working, textile processing, or bathing, and the honest answer is that a single site may have served several purposes across its period of use. What makes them consistently interesting is their ordinariness: these were not ceremonial monuments but working places, patches of ground where people returned repeatedly to carry out the practical business of daily or seasonal life.