The discovery was a souterrain, an underground stone-built structure of the kind used throughout early medieval Ireland, most likely for storage or as a place of refuge. What made this one particularly striking was not just its location, snug against one of Kerry's busiest natural harbours, but the suggestion from local knowledge that another passage had already been found in the same field some years earlier, hinting that the ground beneath this ordinary level field may be more thoroughly honeycombed than anyone yet knows.

Before the souterrain was closed up again, it was inspected by Fanning of the Office of Public Works, and the accessible sections were recorded in reasonable detail. The structure was roughly L-shaped in plan, comprising two chambers connected by a narrow creepway. The first chamber was rectangular, oriented north to south, measuring 2.7 metres in length and about one metre wide at its base, though the walls were corbelled inward, a technique where each course of stone projects slightly over the one below, narrowing the space to around 0.7 metres at roof level. Five flat lintels covered the chamber, which stood 1.6 metres high, and entry was made by lifting the southernmost lintel stone. A creepway, built from upright slabs and barely 0.5 metres in both width and height, connected this chamber to a D-shaped second chamber measuring 1.8 metres east to west and one metre north to south. An arch stone placed midway along the creepway constricted the passage further still, to an aperture of just 0.4 metres wide and 0.3 metres high, a deliberately awkward squeeze that would have slowed any unwanted intruder considerably. The second chamber had partly collapsed and been disturbed; no roof slabs remained in place, and a narrow passage leading from its north-west corner could only be traced a short distance before the rubble made further exploration impossible. The structural description was first published in J. Cuppage's 1986 archaeological survey of the Dingle Peninsula.

The souterrain is now inaccessible, sealed after that brief inspection nearly five decades ago. Its interest lies less in what can be seen today and more in what the record implies: a carefully engineered underground complex, sitting quietly beneath farmland within earshot of a harbour that has been in continuous use for centuries, and possibly extending further than was ever fully mapped.