They appear as low, kidney-shaped or crescent mounds of fire-cracked stone and charred earth, typically found close to a water source, and the one at Treanacally in County Mayo is a local example of this widespread but little-discussed monument type. What generated so many of them, across so many centuries, remains a matter of genuine debate among archaeologists.

The basic mechanism behind a burnt mound is reasonably well understood. Stones were heated in a fire and then plunged into a water-filled trough, rapidly bringing the water to a boil. The cracked and spent stones were discarded to one side, and over repeated use this spoil heap built up into the mound that survives today. What the boiling water was actually used for is less settled. Cooking is the most commonly proposed explanation, with the trough functioning as a kind of field kitchen, but proposals have also included bathing, the processing of hides, textile production, and various craft or industrial activities. Most burnt mounds in Ireland date to the Bronze Age, roughly 2000 to 500 BC, though some continued in use into the Iron Age. They are known in the Irish archaeological literature by the term fulacht fiadh, a phrase traditionally associated with outdoor cooking, though the term's precise original meaning is disputed. Treanacally sits in a part of Mayo where the boggy, water-retentive landscape would have made the necessary water supply easy to come by, which may partly explain the monument's location.