A rath, as this type of ringfort is commonly called, was a roughly circular enclosure used during the early medieval period, typically as a farmstead or the defended home of a local farming family. This one, near Greagh, measures about thirty metres across and looks out eastward towards Lough Allen, the lake lying roughly a kilometre away across the landscape.

The enclosure is defined by an earthen bank, still surviving to between half a metre and just over a metre and a half on its eastern and southern sides, and a fosse, the term for the ditch dug to create the bank material, running along the north-western to south-western arc. That fosse is now partially filled and partially recut as a field drain, evidence of how agricultural use has quietly reworked the site over the centuries. A field bank on the western side cuts across the fosse entirely, truncating what would once have been a continuous defensive circuit. The entrance, a ramp about four and a half metres wide, opens to the east, which is a relatively common orientation for ringfort entrances and may reflect practical considerations around morning light or the direction of approach. The western side of the enclosure relies on a natural scarp rather than a built-up bank, suggesting the builders were content to let the drumlin topography do some of the work for them.

The drumlin ridge setting is worth noting in itself. Drumlins, the smooth elongated hills formed by glacial action, are thickly clustered across this part of Connacht, and early farmers clearly favoured their elevated, well-drained tops for settlement. From this particular ridge, the view towards Lough Allen would have been a useful one, offering sightlines across a significant stretch of the surrounding country.