The trees have taken root not just inside the enclosure but along the bank and fosse themselves, so that the defensive boundary of what was once a farmstead has become, over time, a circular plantation.

Ringforts, known in Irish as raths when they are earthen rather than stone-built, are among the most common archaeological monuments in Ireland, with an estimated 40,000 or more surviving across the country. Most date to the early medieval period, roughly between the fifth and twelfth centuries, and functioned as enclosed farmsteads for individual family groups, the bank and fosse providing security for livestock as much as for people. The fosse is simply the external ditch from which material was dug to build up the bank. At Ballynacarriga, that bank still stands to about 1.3 metres in height, with the fosse reaching a depth of around 1.5 metres. The enclosure itself is nearly circular, measuring 31 metres east to west and just over 30 metres north to south. Two gaps in the bank, one to the northeast and one to the southwest, preserve evidence of original causeways, the deliberate crossing-points that would have served as entrances to the enclosed space within.