Within a radius of roughly 240 metres across the same undulating Mayo pasture, three other raths sit within plain sight of it, turning an otherwise ordinary field into something closer to a prehistoric neighbourhood. The site at Barnycarroll occupies a natural rise with open views in every direction, which is exactly the kind of elevated, commanding position that the builders of such enclosures tended to favour.

A rath is an earthen ringfort, the most common monument type in the Irish landscape, typically dating to the early medieval period, roughly 500 to 1000 AD, and generally interpreted as a defended farmstead or high-status residence. This example is a roughly circular enclosure measuring 32 metres north to south and 29 metres east to west, defined by a scarp, a steep slope cut into the earth, with an external fosse, or ditch, running around its perimeter. The southern half remains relatively well preserved: the scarp still stands to about 1.7 metres in height with a slope width of 2.7 metres, and the fosse survives as a shallow depression roughly 1.8 metres wide. The northern half tells a different story. A field fence following a townland boundary cuts across the rath just south of its centre, and north of that line the monument has been almost entirely levelled. Its presence there can only be read now as a faint rise in the ground, with the ghost of an infilled ditch just barely legible beneath the grass. Gorse has colonised the scarp on the southern side, which is common enough on earthworks that have been left undisturbed long enough for scrub to take hold.