The one at Clooneen in County Clare is, on the surface, unremarkable in that respect, which is precisely what makes it worth pausing over. These low, horseshoe-shaped mounds, typically found near water, are the remains of ancient cooking sites, though that explanation has never quite satisfied everyone. The basic method is well established: stones were heated in a fire, dropped into a water-filled trough, and used to bring the water to a boil. The mound itself is the accumulated debris of cracked and spent stones, discarded after each heating cycle. Most date to the Bronze Age, roughly 1500 to 500 BC, though some are earlier or later.

What archaeologists have debated for decades is what, exactly, was being cooked, or whether cooking was even the primary purpose. Experiments have shown that fulachtaí fia work efficiently as saunas, dyeing vats, or even brewing vessels, and the question remains genuinely open. The Clooneen example sits within a part of Clare that retains a quiet density of prehistoric activity, a landscape that was clearly well settled long before written record. The placename Clooneen derives from the Irish cluainín, meaning a small meadow, the kind of low-lying, damp ground where fulachtaí fia are almost invariably found, close to a stream or boggy hollow that would have supplied the necessary water.