It is, in fact, the remnant of a fulacht fia, one of the most common yet persistently puzzling monument types in the Irish archaeological record. These sites, found in their thousands across Ireland, typically consist of a mound of fire-cracked stone accumulated beside a trough, into which water was heated by dropping in stones that had been superheated in a nearby fire. What they were actually used for, whether cooking, bathing, brewing, or some combination of purposes, remains a matter of genuine debate among archaeologists.

The Tisaxon Beg example is modest in scale but legible enough in the landscape. The spread of burnt material measures roughly 18.5 metres north to south and 16.3 metres east to west, dimensions that place it in the middle range for this type of site. It sits in tillage ground, approximately 80 metres from the river, which is exactly where you would expect to find a fulacht fia. Proximity to fresh water was a practical necessity for whatever activity the site supported, and the Bandon river would have provided a reliable source. The Bronze Age is the period most commonly associated with fulachta fia in Ireland, though some sites have produced dates ranging considerably earlier or later.