During archaeological monitoring of the Lough Mask Regional Water Supply Scheme between 2001 and 2002, a fulacht fia emerged at Carrowcor, Co. Mayo, sitting precisely at the boundary between a glacial ridge and an expanse of low-lying, deep peat. A fulacht fia is a type of prehistoric burnt mound, found widely across Ireland, and generally interpreted as a site where water was heated by dropping fire-cracked stones into a trough, most likely for cooking or other purposes requiring hot water. This one had been knocked about by centuries of land reclamation and farming before the pipeline work brought it to archaeologists' attention.

What the subsequent excavation revealed was a spread of sandstone fragments in charcoal-rich peaty soil, the mound sitting over a layer of marl and then peat beneath. The excavated portion measured roughly 6.2 metres north to south and 6 metres east to west, at a depth of around 27 centimetres, and part of the mound still extends southward, unexcavated, beyond the pipeline corridor. On the western side, a shallow rectangular cut in the marl, measuring about 1.5 metres by 0.8 metres, may represent the outline of a wooden or stone trough, the working heart of the site. The finds recovered were varied and suggestive of a busy place: ten chert flakes, a quartz flake, a chert end scraper, a quartz hammerstone, and a polished stone axe, alongside 58 fragments of bone from pig, cattle, and horse. A radiocarbon date derived from a charcoal sample placed the site at 2890 plus or minus 45 BP, corresponding to roughly 1220 to 920 BC and placing it in the early stages of the Late Bronze Age. Notably, a second fulacht fia lies just 30 metres to the west, suggesting this particular spot, at the edge of the bog and the ridge, was a place people returned to repeatedly.