Historical records confirm the castle’s existence by 1574, when Edmund O’Flaherty held possession of the stronghold. The location’s name hints at its defensive heritage; the Irish ‘dún’ refers to a fort or fortified dwelling, suggesting this dramatic outcrop has served as a strategic strongpoint for centuries.

Today, visitors to the site will find only tantalising traces of the medieval castle that once stood here. The foundations remain visible, along with fragmentary sections of what appears to be a bawn wall running along the western and northern edges of the rocky promontory. These defensive walls, typical of Irish tower houses and castles, would have enclosed a courtyard area providing additional protection for the castle’s inhabitants and their livestock during times of conflict.

A later rectangular building, measuring approximately 16.5 metres in length and 5.1 metres wide, now dominates the northwest corner of the outcrop. This structure, which runs east to west, has incorporated portions of the earlier castle’s defensive wall into its construction. Its tall gable end and foundations represent the most substantial architectural remains on the site, offering a glimpse into the layers of history that have accumulated on this windswept outcrop overlooking Streamstown Bay.