The idea was straightforward enough. A narrow neck of land connecting a sea-jutting headland to the mainland required only a single earthen or stone rampart across it, and the cliffs did the rest. The result was a defended enclosure requiring minimal effort to hold, with the Atlantic doing the work on three sides.

Dunowen, whose name likely derives from the Irish for fort, sits among a considerable number of such coastal sites scattered along the Cork and Kerry shorelines. Promontory forts are found all around the Irish coast, and while some have been excavated and dated with precision, many remain unexcavated, their chronology uncertain. They are generally associated with the later prehistoric and early historic periods, though some may have seen use across many centuries. The cliffed headlands of west Cork were clearly considered worth occupying and defending, whether for reasons of security, livestock management, or status. At Dunowen, the headland geometry that made it attractive to those earlier inhabitants is still visible in the landscape, even where the earthworks themselves have been softened by centuries of wind and coastal erosion.