To the untrained eye it reads as a gentle irregularity in the ground, the kind of thing you might cross a dozen times without registering. What it actually represents is one of the most common prehistoric monument types in Ireland, and one of the least understood.

A fulacht fia is, at its most basic, the remains of an ancient cooking or heating site. The typical arrangement involved a trough, often timber-lined or stone-lined and dug into the ground, filled with water. Stones were heated in a nearby fire and then dropped into the trough to bring the water to a boil. Over repeated use, the stones shattered from the thermal shock, and the broken, blackened fragments were piled to the side. Over centuries, those discarded heaps of burnt stone and charcoal-flecked earth became the low spreads that survive today. The Powerstown example measures roughly twenty metres from north to south and eighteen metres from east to west, making it a reasonably substantial accumulation. Most fulachta fiadh in Ireland date to the Bronze Age, broadly speaking the second millennium BC, though some sites have produced dates ranging earlier or later. The precise function remains debated; cooking is the traditional interpretation, but experimental archaeology and close analysis of site layouts have kept open the possibilities of bathing, textile processing, and other industrial uses involving hot water.