On a north-east-facing slope in Ballygambon, County Waterford, a low triangular mound sits quietly overgrown, its modest dimensions, roughly ten metres across and no more than a metre and a half at its highest point, concealing a purpose that goes back thousands of years. What makes it unusual is not its appearance, which is easy enough to walk past without a second glance, but its composition: the mound is made up almost entirely of broken and burnt stones, the characteristic signature of a fulacht fia.

A fulacht fia is a type of Bronze Age cooking or hot-water site found across Ireland in very large numbers. The typical arrangement involved a trough filled with water, into which stones heated in a nearby fire were dropped repeatedly until the water boiled. The discarded, heat-shattered stones accumulated over time into the horseshoe or, as here, triangular mounds that survive today. The Ballygambon example was formally identified on the 1927 edition of the Ordnance Survey six-inch map, which suggests it was recognisable as a distinct earthwork at that point, though the site itself is almost certainly prehistoric in origin. It sits on the north-east-facing slope of a ridge running roughly north-west to south-east, a topographic setting that is fairly typical for these sites, which are often found near low-lying or damp ground where a reliable water source would once have been available.