The example at Fahee in County Clare sits in a clearing amid mixed scrub, exposed limestone pavement and rough grazing, an unassuming grass-covered mound that would be easy to walk past without a second glance. What it represents, however, is a technology repeated across Bronze Age Ireland with remarkable consistency: a trough, usually timber-lined, filled with water and heated by dropping fire-cracked stones into it until the water boiled. The burnt stone and ash still visible in places within the Fahee mound are the direct residue of that process.

The mound itself is well-defined despite its grass cover, running roughly 12 metres north to south and 9.8 metres east to west, and rising between 0.4 and 0.8 metres above the surrounding ground. That irregular shape is typical; fulachtaí fia tend to accumulate as horseshoe or kidney-shaped spreads of fire-shattered stone and charcoal, the debris of repeated heating episodes piled up around the trough over what may have been generations of use. What the sites were actually used for remains a matter of debate among archaeologists: cooking is the traditional explanation, but experimental work has also demonstrated their viability for brewing, textile processing, and bathing. The Fahee example was brought to formal attention by Tom Coffey, whose report forms part of the Sites and Monuments Record.