These sites, found in their thousands across Ireland, are essentially ancient cooking or heating places, typically consisting of a mound of burnt and shattered stone alongside a water-filled trough. Stones were heated in a fire and then dropped into the trough to raise the water temperature, a process that gradually produced the cracked, heat-reddened debris that gives the mound its distinctive character.

The Rathmore site was modest in scale but clear enough in its layout. The spread of burnt material measured eleven metres by seven metres and covered a subrectangular trough, a roughly oblong pit cut into the ground, measuring 2.2 metres by 1.5 metres. At each corner of the trough, large post-holes had been dug, suggesting that some kind of timber superstructure once stood over or around it, perhaps a frame to support a vessel, a windbreak, or a simple roof. A short distance away, an irregularly shaped pit yielded several sherds of pottery considered likely to date to the Bronze Age, quietly anchoring the site to a period roughly between 2000 and 500 BC. The excavation was carried out in advance of the Newtownmountkennedy to Ballynabarny road improvement scheme, meaning the site was fully recorded and then lost to the new road corridor, as happens with much of what archaeology retrieves from the ground ahead of development.