It is a fulacht fia, a term used to describe the horseshoe-shaped spreads of fire-cracked stone and charcoal that appear in their thousands across Ireland, most often beside streams or in low-lying ground. The name is an old Irish one, loosely translating as something like "cooking place of the deer," though what exactly went on at these sites has kept archaeologists arguing for decades.

Fulachtaí fia, the plural form, date overwhelmingly to the Bronze Age, with the majority falling between roughly 1500 and 500 BC, though some are earlier. The working principle seems straightforward enough: a trough, usually timber-lined or cut into the earth, was filled with water, and stones heated in a nearby fire were dropped in until the water boiled. The cracked, spent stones were then discarded to the sides, building up over time into the characteristic mound that survives today. That much is broadly agreed. Whether the troughs were used primarily for cooking meat, for processing hides, for bathing, for brewing, or for some combination of all these things remains a matter of genuine debate. Experimental archaeology has shown that the method works efficiently for boiling large cuts of meat, but the sites occur in such numbers, and in such varied landscape positions, that a single explanation has always felt insufficient. The example at Aglish sits within a county that has yielded many such monuments, quietly embedded in farmland that has been worked continuously since long after these fires went cold.