That sequence of deliberate action and swift erasure is the central puzzle of this site. A ring-ditch, in general terms, is a roughly circular trench that often marks the boundary of a prehistoric funerary or ceremonial enclosure, sometimes the ghost of a long-vanished burial mound. What makes Corballis unusual is the evidence of two distinct phases of construction, one laid almost directly on top of the other, and the curiously rapid infilling of the first, with no silting at the base of the ditch to suggest it was left open for any length of time.

The site was invisible until 2005, when a geophysical survey picked it out along with two burnt mounds in the same and adjoining fields. Burnt mounds, to gloss the term briefly, are accumulations of heat-shattered stone associated with prehistoric cooking or industrial activity, and their proximity here hints at a broader pattern of use across this ridge. Test excavations followed in 2006, but the ring-ditch was not fully opened until 2017, when road construction for the Donabate Distributor Road made full excavation necessary. The work was carried out by Liam Coen of Archer Heritage Planning. What emerged was a circular enclosure roughly 16 metres in diameter. The earlier phase was defined by a broad, deep v-shaped fosse, a fosse being simply a trench or ditch, packed with sterile fill suggesting rapid backfilling. The later phase cut into that earlier ditch with a shallower, u-shaped fosse, this one rich with charcoal and entered from the east through a gap flanked by two rounded terminals, with a single post pit at the centre. No internal features survived. From the upper ditch fill came a handful of lithic fragments, burnt bone, and a small stone bead with a narrowed central waist, compared by excavators to a dumbbell in form.

The site itself now lies beneath or alongside the Donabate Distributor Road, having been excavated in advance of that construction. For those interested in the broader landscape, the ridge at Corballis sits with sea views to the east and the Broadmeadow river estuary visible to the south, a position that would have made it conspicuous from a considerable distance in any period. The excavation records are held under licence numbers 06E0027 and 17E0407, and the published references from Baker (2006) and Frazer (2007) provide the geophysical survey background for anyone wishing to follow the evidence further.