The Lough Mask Regional Water Supply Scheme, monitored archaeologically between 2001 and 2002, cut across a low, irregular mound of sandstone fragments bound in charcoal-rich soil at Carrowcor in County Mayo. Beneath the disturbed surface, workers and archaeologists found something considerably older than any pipeline: a fulacht fia, the term used for a type of prehistoric burnt mound, typically interpreted as a cooking site where water was heated by dropping fire-cracked stones into a trough or pit.

The site sits at a telling junction in the landscape, where a glacial ridge meets an area of low-lying, deep peat. That combination, elevated ground beside a wet, boggy expanse, is almost a signature setting for these monuments, and this one fits the pattern closely. Radiocarbon dating of two charcoal samples placed activity at the site firmly in the latter stages of the Early Bronze Age, with dates clustering between roughly 1896 and 1676 BC. The excavated portion of the mound measured 10.25 metres north to south and 8 metres east to west, though part of it remains in the ground to the south, beyond the corridor disturbed by the pipeline works. At the western edge of the excavated area, a shallow rectangular feature cut into the underlying marl layer was identified as a possible trough, the functional heart of a fulacht fia where heated stones would have been used to bring water to the boil. Alongside the structural evidence, excavators recovered ten worked stone artefacts in chert, flint, and quartz, including a flint hollow scraper, a flint end scraper, and a retouched chert blade. More unexpectedly, 147 fragments of pig and cattle bone also came up, adding a dimension of animal husbandry or butchery to the site's biography. And the Carrowcor site is not alone in its field: a second fulacht fia lies just 30 metres to the east, raising the possibility that this corner of Mayo once saw repeated, purposeful use across generations of Early Bronze Age people going about the ordinary business of preparing food.