Roughly forty-five metres across, the enclosure sits quietly in the landscape, its earthen bank still standing over a metre and a half high on the outside, and the whole perimeter originally faced with stone on the inner side. Much of that stonework is now hidden beneath slippage and vegetation, but the underlying structure remains largely intact, including the original entrance gap to the south-south-east, still a clean three metres wide.

Ringforts, known in Irish as raths when formed from earthen banks rather than stone, were the dominant form of enclosed farmstead in early medieval Ireland, broadly from around the fifth to the twelfth century. Most housed a single farming family, and the bank and fosse, a shallow defensive ditch encircling the exterior, served as much to pen livestock and mark territory as to defend against attack. At Glashaboy, the fosse survives as a gentle slope down to the base of the bank on the north-north-east to south-east arc, giving a sense of how the enclosure once presented itself to the outside world. What makes this particular example quietly unusual is the combination of two internal features. A souterrain occupies the northern quadrant; souterrains are man-made underground passages or chambers, typically built from stone, and they appear frequently in association with ringforts, probably used for cool storage and possibly as refuges. Running from near the north bank southward through the centre towards the entrance is a low ridge, roughly twenty-six metres long and five metres wide. Its function is not stated explicitly, but such earthen ridges within ringfort interiors are sometimes interpreted as the buried remains of a structure, or as a deliberate platform within the enclosure.