What the Ordnance Survey cartographers of 1837 simply labelled "Cave" on their six-inch map is, in fact, a souterrain, an underground structure of the kind built throughout early medieval Ireland, typically as a place of storage, refuge, or both, often constructed within or beneath a rath, the circular earthwork enclosure that was the standard farmstead of the period.

This souterrain sits in the north-western quadrant of just such a rath, and its three points of surface collapse give a rough sense of its layout beneath. The largest opening, around 1.4 metres across, drops into a lintelled passage, roofed with flat capstones in the manner typical of the form, just 0.85 metres wide and 0.5 metres high, barely enough to crawl through. It runs south-eastward for three to four metres before curving to the south-south-east, and at the bend there appears to be a secondary opening to the north-west, possibly a creep, a narrow connecting squeeze between chambers. The walls here are neatly built of small, thin slabs laid in careful horizontal courses. A second surface opening, much smaller at roughly 0.4 metres across, reveals a separate passage some five metres to the south-south-west, this one sloping noticeably downward toward the north-west, its walls built from medium to large rounded stones rather than the tidy slabs of the first. A third disturbance nearby is stone-filled and inaccessible, though a slab protruding from the turf close by may be a lintel still lying in its original position. By 1919, the feature had disappeared entirely from the revised Ordnance Survey edition, the land surface having presumably closed over it well enough that surveyors either missed it or judged it no longer worth recording.