What they found was a fulacht fia, a type of prehistoric cooking or processing site found in great numbers across Ireland, typically identified by a mound of fire-cracked stone and the remains of a water-filled trough into which heated stones were dropped to boil the water. The example at Danganbeg was badly disturbed by the time archaeologists reached it, but enough survived to reveal a spread of burnt material measuring roughly six metres north to south and four metres east to west.

Excavated in 2007 under licence as part of the N9/N10 Kilcullen to Waterford road scheme, the site proved more complex than a simple cooking pit. Two troughs were uncovered: one flat-bottomed and roughly rectangular, the other linear, with four pits cut immediately to its west. A possible water cistern lay to the east, and a concentration of post-holes between the two troughs hints at some form of timber structure, though its precise purpose is difficult to establish from the surviving evidence. A hearth was found at the western edge of the excavation area, and some ten metres to its north-east a small slot-trench holding four post-holes was associated with intercutting pits. Radiocarbon dating placed the hearth's use somewhere in the range of 41 cal BC to cal AD 55, spanning the late Iron Age and the very earliest Roman period elsewhere in Europe, though Ireland remained outside Roman influence. A separate post-hole returned an earlier date of 762 to 416 cal BC, suggesting the slope at Danganbeg saw activity across several centuries of later prehistory, with different phases of use leaving their traces in the same patch of ground.