The subsidence is not dramatic, but it is legible to anyone who knows what to look for, a slow collapse that has been quietly announcing itself for decades.

The structure is a souterrain, an underground stone-built passage of the kind commonly associated with Early Medieval ringforts across Ireland. Souterrains were typically used for cold storage or refuge, constructed by corbelling, a technique in which stones are laid in overlapping courses that lean progressively inward to form a roof without mortar or formal arches. This one sits within the southern half of a ringfort, a circular enclosure defined by earthen banks that would once have enclosed a farmstead or small settlement. Hartnett investigated the site in 1930, and McCarthy, writing in 1977, recorded what the passage looked like at that point: roughly 0.7 metres wide and 0.75 metres high, with irregularly coursed corbelled walls and some capstones lying just 20 centimetres below the surface. That proximity to ground level helps explain why the structure has since collapsed; the roof was always vulnerable, and time, weight, and soil movement have done their work.