That kind of casual repurposing is not unusual in rural Ireland, where ancient enclosures have been pressed into service as cattle pens, garden plots, and, apparently, convenient shortcuts, but it does give this site an oddly layered quality: the older boundary quietly absorbed into a newer pattern of movement across the land.

A ringfort, or rath, is a roughly circular enclosure defined by one or more earthen banks and ditches, built predominantly during the early medieval period as a farmstead or place of habitation. The Farranastig example sits on a break in a north-facing slope, now in pasture, and measures 29 metres across on its north-south axis. Its enclosing bank still stands to a height of 1.1 metres and retains internal stone facing along its south-eastern arc, suggesting some care in the original construction. Outside the bank, a fosse, the accompanying ditch that would have made the whole structure more defensible or at least more imposing, survives to a depth of 0.9 metres on the southern side, where a field fence has come to rest against it. The 1842 Ordnance Survey six-inch map shows the laneway already crossing the interior on a north-east to south-west axis, and the gaps it required in the bank, 3.4 metres wide to the north-east and 2.7 metres to the south-west, are still visible today. A later roadway skirts around the outside of the bank to the west and north, giving the site a curiously well-travelled feel for something over a thousand years old.