This is a rath, the Irish term for a ringfort, the most common type of early medieval enclosure in Ireland. Typically dating from roughly the sixth to the tenth century, raths were farmsteads, the defended homesteads of farming families rather than military strongholds, though the word "defended" needs some qualification at this particular example.

The rath at Farranmacfarrell is a double-banked enclosure, meaning it has two concentric earthen banks separated by a fosse, a shallow ditch designed to make the outer bank appear more imposing from outside. The inner bank, roughly circular and measuring around 23 metres across, is faced with stone on its western side, a detail that suggests either a preference for solidity in that direction or, more prosaically, that stone was readily available there. The inner bank stands almost two metres high on the exterior but has been worn or levelled nearly flat on the northeast. The fosse between the two banks is well preserved around the western arc but fades to a shallow depression on the eastern side, where time and agricultural activity have taken their toll. A field fence has cut across the outer bank at the south, and the outer bank itself survives better on the west than the east. A gap of about three metres in the outer bank on the eastern side may be the original entrance, which would have faced toward more workable ground. Most intriguing is a sod-covered line of stones running on a northwest to southeast axis across the interior, to the northeast of centre, its purpose unrecorded. It could represent a partition wall, a drain, or something else entirely that the ground has not yet given up.