They tend to appear as low, horseshoe-shaped mounds of fire-cracked stone, the accumulated debris of repeated heating and quenching, and for a long time their purpose was debated. The prevailing interpretation is that they functioned as cooking sites, where stones heated in a fire were dropped into a water-filled trough to bring it to the boil. The example at Ballyvaltron in Co. Wicklow adds quietly to that picture, even if what survives of its excavation record is modest.

The site came to light during groundworks along the N11 route, the kind of infrastructure project that has inadvertently done more for Irish prehistoric archaeology than almost anything else. A partial excavation carried out by archaeologist Goorik Dehaene uncovered two key features: a possible trough cut into the clay subsoil, the vessel into which water would have been poured and heated, and a burnt spread, the scorched and ashy residue characteristic of sustained fire use nearby. Two radiocarbon dates taken from material within the trough fill placed its use in the mid to late Bronze Age, broadly somewhere in the period between around 1500 and 600 BC, though the notes do not specify the precise date range returned. It is a small excavation, partial by necessity, but the combination of trough and burnt material is exactly the signature these sites leave behind.