Though only fragments remain today, this site carries centuries of history within its weathered stones. During the reign of Elizabeth I, the castle served as a prison for the Earl of Desmond, one of many Irish nobles who found themselves at odds with English rule. The castle’s strategic position would later see it play host to James II himself, who reportedly spent a night here whilst fleeing from his defeat at the Battle of the Boyne in 1690.

Historical records confirm the castle’s significance; it appears clearly marked on the Down Survey maps of 1655-6, those detailed documents created following Cromwell’s conquest of Ireland. What visitors find today, however, tells a different story from the fortress that once commanded this hillside. The most prominent surviving feature is a tall masonry pier, roughly 4.5 metres in height and L-shaped in plan, with a mysterious rectangular recess set into its western face above head height. South of this structure lies an area of collapsed stonework, whilst to the east, a double-arched feature, likely added during the 18th or 19th century, hints at later modifications to the site.

Access to the ruins follows an old avenue that once led to Feltrim House, offering visitors a glimpse into the layers of history that characterise this corner of Dublin. From medieval stronghold to Elizabethan prison, from royal refuge to romantic ruin, Fagan’s Castle embodies the complex narrative of Irish history, where power, rebellion, and survival have left their marks in stone and story alike.