The friction wore away enough of the mound's northern face to expose a compact deposit of heat-fractured stones and faint traces of charcoal, sitting just beneath the surface. Without that accidental erosion, there would be nothing visible here at all.

A fulacht fia is a type of Bronze Age cooking place found in great numbers across Ireland, typically located near a water source. The basic method involved heating stones in a fire until they were intensely hot, then dropping them into a water-filled trough to bring it to the boil. The stones, cracked and spent after repeated use, were discarded into a mound beside the trough, and it is these distinctive spreads of fire-shattered stone that archaeologists recognise as the signature of the site type. At Ballytoohy More, the fulacht fia sits on the southern bank of a small shallow stream in a flat-bottomed valley to the west of the island's North Road. The deposit exposed by the sheep measures roughly one metre across and about 25 centimetres thick, a modest remnant by any measure. Roughly 28.5 metres to the east, along the same stream bank, are the remains of what may be a house, suggesting a broader pattern of activity in this corner of the valley. The old boundary of earth and large boulders that runs east to west along the stream's southern bank is itself curious: it appears to have been deliberately positioned to channel the water, and may incorporate material thrown up when the stream was originally modified. Whether the charcoal-flecked stone deposit sits in its original position or has been disturbed and redeposited at some later point remains an open question.