The principle was simple enough: heat stones in a fire, drop them into a water-filled trough, and bring the water rapidly to a boil. The spent, shattered stones accumulate into a mound of blackened material, and it is these distinctive spreads of burnt debris, often crescent-shaped and usually beside water, that survive into the present. What made the Holdenstown example notable was not any single dramatic find, but the evidence it offered of a site used, abandoned, and used again across a very long span of time.

The excavation took place in 2007 under licence as part of the N9/N10 Kilcullen to Waterford road improvement scheme. When archaeologists opened the site, they found a spread of burnt material measuring roughly 21 metres by 22 metres, which sealed a trough and what appeared to be a working platform nearby. Four pits surrounded the trough, and a further four pits to the east of the main spread were filled with burnt mound material, suggesting organised activity around the central feature rather than casual or accidental accumulation. Radiocarbon dating of hazel charcoal taken from the trough fill returned a date of 765 to 420 cal BC, placing that phase of use in the Late Bronze Age or early Iron Age. A separate date from one of the pits, however, came back as 2018 to 1881 cal BC, firmly in the Early Bronze Age, indicating that people were using this spot beside the same small stream roughly a thousand years before the trough was filled for the last time. The site sits on flat ground with a stream running to the north, the kind of modest, unassuming landscape that these sites consistently favour.