The principle was straightforward: stones were heated in a fire, then dropped into a water-filled trough until the contents boiled or reached the required temperature. The mounds that remain are simply the accumulated debris of that repeated process, stones discarded after each use because they fractured and became useless. What makes the example at Coonagh West quietly remarkable is the degree of detail that survived, detail which only came to light because a road-building project made excavation necessary.

The site sits in flat, wet pasture about 300 metres east of the River Shannon, on the edge of what was once active flood-plain. Excavations carried out ahead of the Limerick Southern Ring Road, published by Birmingham and colleagues in 2013 and by Reilly in 2006, revealed a site measuring 36 metres by 23 metres overall, containing two distinct burnt-stone deposits separated by a flowing water channel. The two mounds occupied small islands of relatively higher, drier ground within this wet landscape. At the centre of the first mound, close to the stream edge, excavators found a wooden trough constructed from alder timber, set into a trapezoidal cut oriented northwest to southeast and measuring 1.2 metres long. The trough timbers were held in place by corner stakes and were well preserved, with toolmarks still visible on many of the planks. Flat stones had been laid across the base, and beneath them, traces of grass or reeds survived from the old ground surface. Perhaps the most evocative find was a large Y-shaped artefact of worked ash, discovered among the burnt sandstones. Reilly suggested it had likely been used to manoeuvre hot stones from the fire into the trough, or to lift objects out of the scalding water, and that it appeared to have been simply dropped and left.

The site is not publicly accessible as a visitor destination; it was excavated as a rescue operation in advance of construction, and the ground in this area has since been significantly altered by the ring road. The interest here is less in visiting than in knowing the excavation records exist, held in the published reports by Reilly and Birmingham. For anyone drawn to the mechanics of prehistoric daily life, the Coonagh West assemblage, particularly the trough with its toolmarked timbers and that discarded forked implement still lying among the stones, offers an unusually direct glimpse of a Bronze Age afternoon's work.