The example at Ballycarran in County Kilkenny operates on the same principle but applies it entirely inland, using the River Nore to the west and a stream with marshy ground along the east and south to create a naturally defended tongue of elevated land. The result is a roughly triangular platform of high ground, broad at the north and narrowing to a point of around twenty-two metres at the south, that would have been effectively surrounded by water and bog on three sides.

The site measures approximately 255 metres from north to south and around 216 metres across at its widest northern edge, and it is along that northern side, the one approach that nature alone could not adequately guard, that the fort's builders constructed a fosse. A fosse is simply a defensive ditch, cut to slow or discourage anyone approaching from the unprotected direction. The fosse at Ballycarran does not survive as an obvious earthwork visible from the ground; what gives it away is a cropmark, the faint trace left in growing vegetation when buried features affect how plants draw moisture from the soil. Aerial photography taken on 13 July 1989 recorded a curvilinear cropmark tracing the line of the fosse, and an earlier photograph from 1970 had already caught a portion of the same feature. Both images, taken nearly two decades apart, confirm that beneath the present grass lies the arc of an ancient ditch completing the enclosure of what was once a deliberately chosen and carefully fortified position.

The site sits under grass today and offers little to the naked eye at ground level, which makes the aerial record all the more important for understanding its true scale and layout. The River Nore, still very much present and still defining the western boundary of the promontory, gives some sense of why this particular spur of land would have appealed to whoever chose it, whenever that was.