It is a fulacht fia, a type of prehistoric cooking site found in enormous numbers across Ireland, and one that is easy to walk past without recognising for what it is. The mound itself is made not of earth but of burnt and fire-cracked stone, the accumulated debris of repeated use over generations. Water would have been heated in a trough, likely timber-lined, by dropping stones heated in a nearby fire directly into the water; the stones shatter and blacken with repeated heating and cooling, and it is this characteristic burnt material that builds up into the distinctive horseshoe-shaped mounds still visible today.

The mound at Scarteen measures roughly thirteen metres in length and just under nineteen metres in width, rising only about half a metre above the surrounding ground. Its opening, nearly six metres wide, faces to the north-west. The marshy setting is typical; fulachtaí fia are almost always found near water or in low-lying wet ground, which would have provided a ready source for the trough. Though often described as Bronze Age cooking sites, their precise function has been debated, with some researchers suggesting they may also have served for bathing, textile processing, or other purposes requiring heated water. Whatever its original use, the Scarteen example has survived in the ground precisely because the boggy conditions that made the site practical in prehistory have also helped preserve it across the millennia.