A rath, as this type of earthwork is commonly known, was typically a circular enclosed settlement of the early medieval period, built from raised banks and ditches to define a farmstead or the home of a local family of some standing. Here at Pruntus, the surviving earthwork sits in pasture roughly a hundred metres south-east of the Awbeg River, a low but still perceptible presence in an otherwise ordinary field.

The platform itself measures approximately 44 metres east-north-east to west-south-west and 38 metres south-south-east to north-north-west, raised about 0.6 metres above the surrounding ground. A fosse, which is simply a defensive or boundary ditch dug around such an enclosure, runs around part of the circuit, deepest to the north-east where it reaches 0.7 metres in depth and about 4 metres in width. Outside that, an earth bank rises to 1.5 metres at its highest points to the north and south, where it has been absorbed into the modern field fence system over the centuries. To the south-east the bank is much reduced, grass-covered and barely visible, and a faint outer fosse to the east survives only as a shallow trace, no more than 0.6 metres deep. The railway that clips the south-west to north-west arc of the site removed whatever once stood there, though the remaining circuit is coherent enough to read as a whole. Inside, the ground is crossed by cultivation ridges running roughly north-north-west to south-south-east, suggesting the enclosed area was worked as agricultural ground at some point after the rath's original function had passed.