These are fulachtaí fia, a term used for the horseshoe-shaped or mounded accumulations of fire-cracked stone that are among the most common prehistoric monuments on the Irish landscape. The working principle, as archaeologists understand it, was straightforward: stones were heated in a fire and then dropped into a water-filled trough, bringing it to a boil. The stones would crack and split with repeated heating, and the broken fragments were raked aside, accumulating over time into the low mounds that survive today.

When fieldwork was carried out at this Lisdowney site in 1987, three such mounds were identified sitting close together on the wet ground just above a stream course, with the stream presumably supplying the water the process required. The smallest of the three measured around seven metres across, the middle mound approximately ten metres, and the largest, positioned in the north-east corner of the field, reached about twelve metres in diameter. That largest mound also retained at least three trough depressions, the hollows where the actual heating of water would have taken place. The grouping of three separate mounds in such proximity is relatively unusual and suggests the site saw repeated or sustained use over time.

By 2018, when satellite imagery was reviewed, the field had been reclaimed and the original field boundaries removed. Whether the mounds themselves survive beneath the altered ground surface is unclear, but the physical changes to the landscape mean that what was once a legible prehistoric site in open boggy ground has since been absorbed into a worked agricultural field.