When road workers began stripping topsoil for the Celbridge Interchange in 2001, they exposed something that had not seen daylight since the Late Bronze Age: a system of ditches, pits, and hearth areas arranged around a central ring-ditch, apparently used not for burying people but for animals, and in ways that suggest something more deliberate than simple refuse disposal.

Excavation carried out under licence that same year revealed three ditches enclosing an area roughly 35 metres east to west and 25 metres north to south. The largest of these, around 2 metres wide and 1.3 metres deep, curved to follow the line of the central ring-ditch before straightening again, a detail that strongly implies both features were in use at the same time. A ring-ditch is typically a circular or near-circular trench, often associated in Irish prehistory with burial or ritual activity, though what was deposited here was entirely animal in origin. The fill of the main ditch contained large quantities of animal bone, with a notably high proportion of skulls. In the fill of a second, shallower east-west ditch, excavators found the complete skeleton of a small horse or pony, placed whole rather than scattered. Elsewhere across the complex, small pits and burnt hearth areas contained cremated animal bone. No human remains were found anywhere on the site. The assemblage, taken together, points to the Late Bronze Age, roughly 1200 to 600 BC, a period in Ireland when enclosures of this kind sometimes served ceremonial or feasting functions rather than purely agricultural ones.

The site no longer exists as a visible feature. It was uncovered during infrastructure work and subsequently built over as part of the interchange development, which means the archaeology survives now only in excavation records and finds. What it leaves behind is a question about the people who filled those ditches: why so many skulls, why one complete horse, and what, if anything, was being marked or concluded in that enclosed ground outside what is now Castletown.