The site matches, on the surface, the profile of a fulacht fia, the term used for the characteristically mound-shaped prehistoric cooking sites found in their thousands across Ireland, typically identified by spreads of fire-cracked stone and charcoal left behind after repeated episodes of water-boiling in a timber-lined trough. But when excavator Catherine McLoughlin examined the evidence, the picture that emerged was considerably more ambiguous.

The site came to light during archaeological monitoring carried out in advance of the N20/N21 Limerick Bypass and was excavated under licence number 99E0525. What McLoughlin uncovered was an artificial platform, constructed from horizontally laid brushwood, peat, and clay, measuring roughly 8.5 metres east to west and 3.5 metres wide. The timbers were poorly preserved and bore no toolmarks; there were no vertical pegs anchoring them in place. Above this base, a thin layer of tacky grey clay had been laid to create a working surface above the natural water level, and into this surface a shallow, subcircular pit had been cut, roughly 1.24 metres in diameter and no deeper than 0.4 metres. The pit contained two peaty fills but yielded no artefacts whatsoever. Sealing all of this was a layer of heat-shattered sandstone mixed with charcoal, up to 0.3 metres deep, which would ordinarily signal classic fulacht fia activity. The problem is that no trough, no burning in place, and no datable material were found to confirm that cooking actually happened here. McLoughlin noted that a well-established fulacht fia site sits approximately 100 metres to the east, and proposed that the stony, charcoal-rich material may simply have been carried from that neighbouring site and deposited at Rathbane South to consolidate or refurbish the platform after its pit had gone out of use.

The site is no longer accessible as a discrete feature; it was identified and recorded as part of road construction groundwork, and nothing visible remains above ground today. Its value is largely interpretive. For anyone following the archaeology of the Limerick Bypass corridor, the published summary appears in McLoughlin's 2000 report, and the excavation record is available through the national excavations database. The site is a reminder that the category of fulacht fia, useful and widely applied as it is, can sometimes describe a deposit rather than an activity, and that prehistoric sites rarely conform neatly to the labels assigned to them.