What remains is a shallow circular depression in the ground, roughly three metres across and less than a metre deep, which may be all that survives of an underground stone-lined passage built, most likely, during the early medieval period. A souterrain, to use the technical term, was a man-made underground structure, typically constructed from dry-stone walling and corbelled or lintelled roofing, used variously for storage, refuge, or concealment. This one, if it ever existed in its complete form, is largely gone.

The 1837 Ordnance Survey six-inch map makes no mention of anything unusual at Skeagh More; the area is recorded simply as a limestone ridge running north to south. By the time the revised twenty-five-inch edition was produced in 1913, however, a small circular feature, approximately three metres in diameter, appears at the southern end of a curvilinear earthwork, annotated with the word "Cave". The earthwork itself is labelled "Sand Pit (Disused)", which tells most of the story. By 1971, when the site was formally described, the curvilinear depression was interpreted as the remains of a relatively modern quarry, and no surface trace of the cave or souterrain could be found. The working theory is that the sand pit removed the bulk of the souterrain's fabric, leaving only the shallow depression that may represent a collapsed chamber. Roughly eighty metres to the south-east sits a ringfort, a circular earthwork enclosure of the kind commonly associated with early medieval settlement in Ireland, and the two features may once have been related, the souterrain serving the farmstead whose boundaries the ringfort defined.