That body of water, recorded as Derrymannin Lough on the 1838 Ordnance Survey six-inch map, has long since been drained, leaving a boggy spread of land about 300 metres to the south-east. The ridge itself commands clear sightlines in most directions, with flat wet ground both to the east and west. It is the kind of position that makes practical sense, and that is precisely why someone chose it.

The structure is a rath, the Irish term for a ringfort, a form of enclosed settlement built mostly during the early medieval period, roughly between the fifth and twelfth centuries, and used as a farmstead by a family of some local standing. This one is modest in scale: a slightly raised circular area measuring approximately 19 metres north to south and 21 metres east to west, enclosed by an earthen bank about 2.8 metres wide. The bank retains traces of stone facing on its inner slope, suggesting it was once more carefully finished than it appears today. Inside, the ground slopes gently downward to the east, and faint cultivation ridges running east to west are still visible, hinting at agricultural use within the enclosure. A shallow depression against the inner face of the bank at the north-east may indicate where a structure once stood, though nothing definitive remains. A gap of roughly two metres in the bank at the south-east is ragged now but could represent the original entrance. Two narrower breaks at the north-north-east and north-west are more clearly the result of erosion over time. A few hawthorn bushes have established themselves along the perimeter, which is otherwise grassed over.