That slight but deliberate depression, combined with walls still readable as a double-faced construction with a rubble core, gives the structure a quiet particularity. A gap at the western end of the north wall is the most likely candidate for a doorway, though no date has been firmly attached to the building, and none of the details that would fix it to a century or a culture have survived in the record.

A cashel is a stone-walled enclosure of early medieval Ireland, typically circular or oval, used to define and defend a farmstead or settlement. This one at Ballynascragh contains at least two house sites within its interior, the rectangular structure in the north-northwest sector measuring 7.4 metres long by 4.9 metres wide, and a second example visible in the eastern sector. The relationship between the two is not established, and it is not known whether they were in use simultaneously or represent different phases of occupation within the same enclosure. What is clear is that someone, at some point, arranged stone into walls here with enough care and skill that the outline is still legible.