The one at Oughtagh occupies a gentle north-east-facing slope in open grassland, almost perfectly circular at 27 metres north to south and 26 metres east to west. What defines it is a combination of a raised bank and an external fosse, the fosse being the ditch dug outside the bank to reinforce the enclosure, with the excavated material typically piled inward to heighten the bank above. Here, the bank is clearest from the west around through the north to the north-north-east, while elsewhere the enclosure is marked by a scarp, a natural-looking slope that is in fact the eroded remnant of the original earthwork. The fosse remains visible from the north-north-east, sweeping through the east and down to the south.

Ringforts of this kind, known in Irish as ráth when they are earthen rather than stone-built, were the dominant form of rural settlement in early medieval Ireland, roughly from the fifth to the twelfth century. They typically enclosed a single farmstead and its outbuildings, the bank and fosse serving less as military fortification and more as a practical barrier against livestock straying and predators entering. The Oughtagh example is in fair condition, which for a structure that may be well over a thousand years old means the essential shape is still readable in the landscape, even if time and agriculture have softened its edges. The proximity of a second ringfort just to the south-south-west suggests this part of north Galway was settled with some density during that period, two households perhaps working adjacent land, or the sites representing successive generations making use of the same favourable ground.