A fulacht fia, the term used for a type of Bronze Age burnt mound typically associated with outdoor cooking or heating water, was recorded at this location and yet evaded inspection when archaeologists went looking for it in 1994. That combination, a site known to exist in theory but absent on the ground, gives this particular monument an oddly spectral quality.

A fulacht fia generally survives as a low, horseshoe-shaped mound of fire-cracked stone and charcoal-rich soil, the accumulated debris of repeated episodes of heating stones in a fire and dropping them into a water-filled trough. They are among the most common prehistoric monuments in Ireland, found especially near streams and wet ground, which makes the setting at Lisleagh entirely typical. What is less typical is the concentration here. During the 1990s, five fulachtaí fia were identified in this one area, forming a cluster that suggests the location was used repeatedly and perhaps over a considerable span of time. Descriptions of four of the group were published in 2000 as part of a broader county inventory, with the fifth, this one, remaining the elusive member of the set. The cluster was brought to attention through the work of M. Monk, whose personal communication is credited with flagging the group in the first place.

The site sits in reclaimed agricultural land, the kind of improved pasture that has a long history of flattening and absorbing the low, subtle earthworks that Bronze Age monuments tend to leave behind. Whether the mound was ploughed out, subsumed into the surrounding ground level, or simply difficult to distinguish from the improved landscape is not recorded. It remains on the books as existing, somewhere near that stream, unverified.