At Ballynamrossagh in County Tipperary, a circular earthwork roughly 26 metres in diameter survives in heavily reduced form on a north-north-west-facing slope. What remains is largely the ghost of itself: a shallow fosse, that is, a ditch dug as part of an enclosure's original boundary, now only about 15 centimetres deep and less than three metres wide in places, tracing an arc from the north-east around to the north-west. A low scarp, a slight step in the ground surface running along the downslope side, marks the monument's outer edge to the north. The interior has been levelled, probably through centuries of agricultural work, and tilts gently downward in line with the natural slope of the hill.

Enclosures of this type are a familiar, if poorly understood, feature of the Irish landscape. Circular or near-circular earthworks defined by a bank and fosse appear across the country in enormous numbers, and their purposes varied considerably: some enclosed early medieval settlements, others may have served as animal pounds or ceremonial spaces. Without excavation it is rarely possible to say which category any single example belongs to. What is more immediately striking at Ballynamrossagh is that this enclosure does not sit alone. A second enclosure lies approximately 30 metres to the north-west, and a third around 60 metres to the east, suggesting that this small slope once supported a cluster of activity rather than a single isolated feature. The commanding views the site affords, ranging from the south-west around to the north-east, would have made it a conspicuous and perhaps deliberate choice of location.