Beneath the compacted surface of that track lies a levelled mound, and at its western edge, where the earth has been cut away, a dark layer of burnt material is visible in section, the mute signature of a fulacht fia.

A fulacht fia is a prehistoric cooking site, typically Bronze Age in origin, characterised by a mound of heat-shattered, fire-cracked stone accumulated beside a water source. The usual interpretation is that stones were heated in a fire and then dropped into a trough of water to bring it to a boil, cooking meat or serving other purposes still debated by archaeologists. The Lisdangan example sits adjacent to a stream, which is entirely typical of the form; proximity to fresh water was not incidental but essential. By 1937, when the Ordnance Survey recorded the site on its six-inch map series, the mound was already clearly visible and was noted as being cut by the stream flowing northwest to southeast across the land. At some point after that record was made, the mound was levelled, most likely in the course of ordinary farm improvement, and the trackway was laid over it. The burnt stone layer exposed at the trackway's edge is now the only part of the site that remains directly visible.