The trapezoidal enclosure, roughly 25 metres along its northeast-southwest axis and between 17 and 20 metres across, was first spotted not on the ground but from the air, when a cropmark revealed the outline of its fosse in aerial photography taken in July 1989. A fosse, in this context, is simply a ditch dug to define or defend a boundary, and what made this one particularly easy to miss was that it forms part of a denser cluster of enclosures and pits, one of which appears to have been built directly over it, obliterating its southwestern edge in the process.

The more detailed picture emerged from excavation carried out by Doody in 1995, as part of the Discovery Programme's Ballyhoura Hills Project, a research initiative focused on the archaeology of the Ballyhoura Hills region straddling Cork and Limerick. A single cutting opened at the northwest side of the enclosure produced a quietly surprising result: where the aerial photograph had suggested a single fosse, there were in fact two, running parallel and just 1.4 metres apart. The inner fosse, which had left no trace visible from the air, was the more complex of the pair, roughly 1.6 metres wide at the surface and asymmetrical in profile, with a steep northwest wall and a distinct step cut into the opposite side. Its fill had accumulated gradually through natural silting rather than deliberate backfilling. The outer fosse was narrower and more regularly shaped. Scattered among these features were stake-holes, a small pit containing heat-shattered stones, what may have been a cultivation furrow, and a short trench with four stake-holes set into its base, suggestive of some kind of structural foundation. The excavator concluded that this enclosure predates the larger subcircular enclosure that now abuts it to the southwest, meaning the site represents at least two distinct phases of activity, one built on top of, and cutting through, the other.