This is a fulacht fia, a type of site found in considerable numbers across Ireland, typically consisting of a burnt mound of heat-shattered stone alongside a water-filled trough. The basic method involved heating stones in a fire and dropping them into the trough to boil water, most likely for cooking meat. What makes the Coarha More example worth attention is how well it survived, and what it yielded when excavated in 1988.

Before excavation, the site presented as a sod-covered mound roughly ten metres by seven metres in plan, with a slab-lined trough visible at its western end. When investigators opened the trough, they found it carefully constructed: the sides formed from regular sandstone slabs set into a pit, the floor a single large rectangular slab, and the whole structure measuring approximately 0.9 metres by 1.4 metres and around 0.6 metres deep. A possible working surface of slabs and clay deposits lay along its southern side. The mound itself was composed of quantities of burnt and fire-shattered sandstone mixed with peat ash and nodules of peat charcoal, the accumulated debris of repeated use. Beneath all the archaeological deposits lay fibrous brown peat, a sample of which returned a radiocarbon date of 2950 plus or minus 80 years before present, placing activity at the site broadly in the later Bronze Age. Among the finds were pottery sherds and a spindle-whorl, the latter an object used in hand-spinning thread, of Early Medieval type, recovered from a sealed deposit associated with the trough. Its presence suggests the site saw at least some activity or reuse well after the Bronze Age period that produced the mound itself.