What makes this rath, as such earthwork ringforts are known in Ireland, quietly interesting is the way its builders adapted their design to the terrain. The interior was deliberately cut into the hillside on the south-south-west side to level the ground within, a practical solution to the awkward business of constructing a circular enclosure on sloping land.

A rath is a ringfort enclosed by earthen banks rather than stone walls, typically dating to the early medieval period in Ireland, roughly 500 to 1000 AD, and understood to represent the defended farmsteads of farming families. This example at Toorreagh is a bivallate rath, meaning it has two concentric earthen banks with a fosse, or ditch, running between them. The outer bank stands to about 1.6 metres in height, the inner to around 0.7 metres, and the fosse reaches its greatest depth of 1.25 metres on the upslope side, where drainage and defence would both have demanded it. Both banks are most pronounced on the downslope side, where the hillside lends them natural drama, but fade to low, almost imperceptible undulations as they curve back uphill. Entrances, visible as gaps in both banks, face roughly north-north-west and south-south-east. The interior surface has its own gentle undulations, though these resolve into no clear pattern, leaving open the question of what once stood inside.