No mound, no hollow, no scatter of scorched stone marks the spot. A fulacht fia, one of Ireland's most common prehistoric monument types, lies somewhere to the east of a local stream, absorbed into land that was long ago drained and levelled for agriculture, leaving nothing visible at the surface.

Fulachtaí fia, found in their thousands across Ireland, are generally understood as Bronze Age cooking sites, typically dated to somewhere between 1500 and 500 BC. The classic form is a horseshoe-shaped mound of heat-shattered stone surrounding a trough, often timber-lined, dug close to a water source. Stones were heated in a fire and then dropped into the water-filled trough to bring it to a boil, a method efficient enough to cook large joints of meat. Over repeated use, the cracked and spent stones were raked out and piled to either side, forming the characteristic mound. The Ballythomas example sits beside a stream in the manner typical of the type, since a reliable water source was essential to the whole process. What sets this particular site apart is simply its invisibility. The land reclamation that erased its surface expression also preserved its location in the archaeological record, noted but unverifiable by eye.