This is a rath, the Irish term for an earthen ringfort, a form of enclosed settlement that was once among the most common features of the Irish countryside. Thousands were built, mostly during the early medieval period, and this one at Ardvarny follows the familiar pattern: a roughly circular interior enclosed by a bank of earth and the remnants of a fosse, the shallow ditch from which that bank material was originally dug.

The internal dimensions here measure approximately 33 metres north to south and 30.5 metres east to west, placing it well within the typical size range for a single-family farmstead of its kind. A break in the southern bank may mark the original entrance, a detail that, if confirmed, would be consistent with many comparable sites where the entrance faces south or south-east. More intriguing is the low earthen mound identified within the enclosed area, which may represent the remains of a hut site, the physical trace of a structure where someone once lived, stored grain, or sheltered livestock. Such mounds are sometimes all that survives of timber or wattle buildings that have long since decayed back into the ground.