Half of it has simply vanished, the eastern portion leaving no trace at the surface, while a field fence now stands in for the missing arc. A shallow quarry pit, dug into the north-western interior at some point, adds to the sense of a landscape that has been quietly worked over and diminished across centuries.

The feature is most likely the remnant of a rath, the Irish term for a roughly circular earthen enclosure, typically dating to the early medieval period and associated with farmsteads or small settlements. What survives measures approximately 26.5 metres north-northeast to south-southwest and 16.6 metres across, placing it in the range typical of such enclosures. Its survival was not even confirmed through conventional map evidence: it does not appear on Ordnance Survey six-inch maps from either 1838 or 1917, and came to archaeological attention only through aerial photography. Thirty metres to the south lies a second rath, similar in scale and form, suggesting this small corner of Rockfield once supported a cluster of related activity rather than a single isolated settlement.

Directly to the west of the main enclosure sits a smaller, roughly D-shaped feature, measuring between fifteen and sixteen metres by just over six. Its low stony banks, no more than thirty centimetres high, and its slightly hollow interior set it apart from the main enclosure in character. It abuts an overgrowth-covered field boundary on one side and is considered a later addition, possibly serving an agricultural or enclosing function distinct from whatever the rath once housed.