This is a rath, a type of ringfort built from earth and stone that served as a farmstead enclosure in early Christian Ireland, typically housing a family of some local standing along with their livestock. What makes the Lisduff example quietly interesting is how thoroughly later generations folded it into the working landscape without quite erasing it.

The rath measures 36 metres north to south and 31 metres east to west, raised into an oval platform on a northwest to southeast ridge overlooking the River Glore valley. The builders compensated for the natural slope by building up the bank on the southern half, a small piece of prehistoric pragmatism still legible in the ground today. The eastern scarp, where it runs alongside an old trackway, was faced at some point with drystone walling standing 1.2 metres high; the western half of the bank, built from earth and stone to between 1.8 and 2 metres wide, was later modified with additional stonework to serve as a field fence. The interior, level and grassy, is used as a small field, entered through a 2.3-metre gap cut into the bank at the southwest. A slump in the scarp at the east-southeast may mark an original entrance that was sealed or obscured when the structure was reworked in more recent centuries. Ordnance Survey maps from 1838 and 1919 both show a boreen skirting the rath on its northern and southeastern sides, associated with a cluster of vernacular cottages immediately to the northeast; the lane survives in part, and the ruins of a few stone cottages can still be found nearby. The rath sits with views opening to the southwest across damp boggy ground in the Glore valley, while undulating terrain, trees, and field fences close things in on the other sides. Its perimeter is thickly overgrown with hawthorn, blackthorn, ash, willow, and brambles, giving the earthwork a density that separates it from the open pasture around it.