The one at Knockranny, in County Mayo, is a quiet example of a type that once formed a routine part of Bronze Age life, its low, horseshoe-shaped mound of burnt and fire-cracked stone sitting as a faint signature of repeated, purposeful activity carried out perhaps three or four thousand years ago.

A fulacht fia, broadly speaking, is the remains of an ancient cooking place, though scholars have long debated whether cooking was always, or even primarily, the point. The typical arrangement involved a timber-lined trough sunk into the ground near a water source, a hearth for heating stones, and the mound itself, which built up gradually from the discarded cracked stone that could no longer hold heat efficiently. Experiments have shown that water in such a trough can be brought to a rolling boil surprisingly quickly using this method. Some researchers have proposed alternative uses, from textile processing to brewing, and the debate has not been fully settled. What is clear is that these sites were used repeatedly over time, often near streams or boggy ground, and that Knockranny fits into a wider pattern of such monuments found throughout Mayo and the rest of Ireland.