What they had disturbed was a fulacht fia, a type of prehistoric cooking site found in considerable numbers across Ireland, though rarely noticed by anyone who has not gone looking for one.

A fulacht fia, sometimes called a burnt mound, is broadly understood to have functioned as an outdoor cooking place, likely dating to the Bronze Age. The typical arrangement involves a trough, often timber-lined or stone-lined, into which water was poured, and then heated by dropping fire-cracked stones from a nearby hearth. The shattered, blackened stones accumulate over time into the horseshoe-shaped mounds that archaeologists recognise across the Irish landscape. The example on Foynes Island was recorded by Denis Power and uploaded to the national record in August 2011. Its exact dimensions and condition were not formally surveyed, but the evidence, a spread of burnt material exposed during plantation work, is consistent with that familiar pattern. The landowner's account of how it came to light is itself a common enough story; commercial forestry has inadvertently revealed many such sites across the country, ploughing through layers that had gone undisturbed since prehistory.

Foynes Island sits in the Shannon Estuary, and access to it is not straightforward for the casual visitor. The site itself lies within a coniferous plantation on a westward-facing slope, which means the tree cover is likely dense and the ground beneath it uneven. There is no formal path or signage marking the location. Anyone with a serious interest in visiting would need to make arrangements with the landowner and go prepared for the typical difficulties of moving through a working plantation, low branches, soft ground, and poor sightlines. The burnt material, if visible at all above the surface, would appear as a spread of darkened, heat-shattered stone rather than any dramatic earthwork. It is the kind of site that rewards patience and a reasonable knowledge of what to look for.