On an east-facing slope in open grassland, the remains of an early medieval ringfort have been slowly absorbed into the terrain around them, their original geometry still legible but only just.

A rath, to use the Irish term, was a circular or near-circular enclosure defined by one or more earthen banks and ditches, used as a farmstead or dwelling site during the early medieval period, roughly the fifth to twelfth centuries. Tens of thousands were built across Ireland, and their survival varies enormously. This example at Ballyglass is subcircular in plan, measuring approximately 45.5 metres north to south and 40 metres east to west. It was originally defined by two earthen banks with an intervening fosse, the fosse being the ditch cut between them to reinforce the defensive or boundary effect. The inner bank is still traceable along the southern and western arcs and at the north, but elsewhere the enclosure is marked only by a degraded scarp, a low slope in the ground where a more substantial bank once stood. The outer bank and fosse survive best from the south-east around through the south and west. A field boundary, probably of much later date, has been laid directly over the outer bank on the south-west to west side, which accounts for some of the erosion and confusion in that portion of the circuit.