These sites, found in their thousands across Ireland, are generally understood to be Bronze Age cooking places, where stones were heated in a fire and then dropped into a water-filled trough to bring it to the boil. The tell-tale sign is the mound of heat-cracked, burnt stone that accumulates over generations of use. At Ballynatona, that mound is considerably flatter than it would have been, levelled at some point during the 1930s, and what survives is an unassuming scatter of burnt material rather than anything that announces itself to the eye.

The levelling, though destructive, did yield one remarkable find. A bronze flanged axehead with a stop ridge, a type of cast metal tool characteristic of the Bronze Age, was recovered from within the mound at a depth of 122 centimetres, resting on roughly 15 centimetres of the same burnt stone material. The axehead is held in the National Museum of Ireland, registered as NMI 1936:1780. The depth at which it was found, well down within the accumulated burnt stone, suggests it had been deposited, lost, or placed there during the active life of the site rather than arriving later. Flanged axeheads with stop ridges are a recognised Bronze Age form, and their presence at a fulacht fia is unusual enough to give this otherwise unremarkable-looking spread of scorched earth a slightly different character.