These low, horseshoe-shaped mounds, typically found near water, are the remnants of ancient cooking sites, places where stones were heated in fire and then dropped into water-filled troughs to bring them to the boil. The mound itself is the accumulated debris of those cracked and shattered stones, discarded after repeated heating and cooling split them beyond further use. The example at Cahercalla in County Clare is one such site, quietly occupying its place in the landscape outside Ennis.

The type is generally dated to the Bronze Age, roughly 1500 to 500 BC, though some examples are earlier or later. Debate among archaeologists about their precise function has never fully settled; cooking is the most widely accepted explanation, but brewing, bathing, and textile processing have all been proposed at various points. What is consistent is the method: fire, stone, water, and the slow accumulation of waste that eventually became the mound a visitor sees today. Cahercolla sits in a part of Clare with considerable archaeological depth, the wider Ennis area having yielded evidence of continuous human activity across many periods, though the specifics of this particular mound's excavation history or condition are not presently documented in detail.