The souterrain, as these tunnel structures are known, was typically built during the early medieval period as a place of refuge or cool storage, dug beneath the domestic space of a farming settlement and roofed with large stone lintels. Its presence here is one of the details that lifts this particular site above a simple earthwork.

The ringfort itself is a rath, meaning an enclosure defined by earthen rather than stone banks, the kind of defended farmstead that was the standard unit of rural life in Ireland roughly between 500 and 1000 AD. This one is nearly circular, measuring 40 metres north to south and 38 metres east to west, and it retains two concentric banks separated by a fosse, the shallow ditch that once helped define the boundary between the settled interior and the open land beyond. The outer bank, which survives most clearly on the western and northern sides and reaches a height of 2.9 metres, is considerably more substantial than the inner one, which has been partially levelled and now presents a wide, uneven profile. A gap on the south-east of the inner bank and another on the north side of the outer bank, roughly eight metres wide, indicate where entrances once existed. Inside, the ground is not flat; it rises to a central east-west ridge, a natural feature of the hillside that the original occupants presumably made use of when choosing their position.