This is a fulacht fia, a type of ancient cooking site found in extraordinary numbers across Ireland, typically dating from the Bronze Age. The basic principle involved heating stones in a fire, dropping them into a water-filled trough to bring it to the boil, and using that heat to cook meat or, as some researchers have argued, for bathing, brewing, or other purposes. The stones, cracked and discoloured by repeated heating and cooling, were discarded into a mound beside the trough, and it is that distinctive horseshoe-shaped spread of burnt material that survives at Killinane today, grassed over and gradually merging back into the landscape.

The site sits immediately north of a well, a detail that is less incidental than it might seem. Fulachtaí fia are almost invariably found close to a reliable water source, whether a stream, a spring, or a well, since the whole process depended on a ready supply. Whether the well here was already in use when the fulacht was active, or represents a later tradition of drawing water from the same convenient spot, is not recorded. What is recorded is that a standing stone lies roughly forty metres to the north-west. Standing stones are among the most enigmatic of prehistoric monuments, and their relationship to nearby fulachtaí fia or other features is rarely straightforward, but the clustering of different monument types within a small area of ground often points to a landscape that held particular significance over a long period.