The rectangular tower house rises from a D-shaped promontory that juts into the sea, connected to the mainland by only a narrow neck of land. Built directly on the cliff face on its northern and western sides, the castle’s position would have made it nearly impossible to attack from the water, whilst providing an excellent vantage point for monitoring maritime traffic entering the harbour.

The tower, constructed from roughly coursed limestone blocks bound with lime mortar, originally stood four storeys high at approximately 18 metres. Its walls, measuring over two metres thick at the base, demonstrate the substantial defensive capabilities typical of Irish tower houses. Though the southeast section has been reduced to its foundations, the north and west walls still stand to their original height. Visitors can identify two separate entrances; one at ground level near the southern end of the east wall, and another at first floor level to the north, the latter featuring corbels that once supported a retractable drawbridge. The first floor doorway, set within a rectangular recess and topped with a pointed arch, leads to a mural passage that would have provided additional security for the castle’s inhabitants.

Inside, the tower reveals the practical design of medieval fortifications, with window embrasures, wall presses for storage, and even a garderobe built into the walls. The first floor was originally covered by a pointed stone vault running east to west, though only the western portion survives today. A small tower at the southwest corner of the second floor once provided access to the wall-walk, where defenders could patrol behind crenellations that appear to have been deliberately damaged, possibly during one of Ireland’s many conflicts. The promontory itself shows evidence of medieval landscaping; the area southeast of the castle was artificially raised to create a level platform, with the fill layer still visible where erosion has exposed a cross-section of the site.