Ringforts, known as raths when they are earthen rather than stone-built, are among the most common archaeological monuments in Ireland, yet each one carries its own specifics, and this one at Lisnagea has held its shape well enough to be measured and mapped in some detail.

The enclosure is roughly circular, with an interior diameter of 26 metres in both directions. It is defined by a steep-sided, round-topped earthen bank, though much of that bank has worn down over centuries into a scarp, a sloped edge rather than a standing wall. Outside it sits a flat-bottomed fosse, the technical term for a deliberately dug ditch, roughly 2.2 metres across at its base, and beyond that an outer bank, lower and narrower than the inner one. Two entrance gaps survive: one to the north, about 2.9 metres wide, and a wider one to the south-east at 5 metres. The whole interior is covered in grass and rushes, with the banks themselves overgrown. These dimensions and details come from Michael J. Moore's Archaeological Inventory of County Leitrim, published by the Stationery Office in Dublin in 2003, which remains the systematic record for monuments of this kind across the county.

The drumlin setting is worth pausing on. Drumlins are the smooth, egg-shaped hills of glacial deposit that cluster thickly across counties like Leitrim, Cavan, and Monaghan, and a ringfort placed on top of one gains considerable natural elevation without requiring any additional earthwork. From such a position, the surrounding low-lying ground would have been clearly visible, and the site itself would have been equally visible to anyone approaching across it.