Known locally as 'Archibold's Castle', this rectangular tower house rises three storeys to a parapet level, its roughly coursed granite masonry and dressed granite corners bearing witness to centuries of coastal weather. The castle's defensive nature is immediately apparent at its western entrance, where a round-headed doorway sits protected by machicolation at parapet level; a medieval feature that allowed defenders to drop objects on unwelcome visitors below.

Inside, a stone spiral staircase leads visitors through the castle's three levels, each revealing different aspects of medieval life. The ground floor contains a long chamber measuring 8.5 metres by 4 metres, illuminated by windows that were inserted in later centuries. Evidence of the castle's many alterations can be seen in the blocked doorway along the western wall, whilst practical storage spaces, known as wall presses, are built into both the eastern and western walls. The first floor, covered by a barrel vault, features an intriguing historical detail: the lintel above its doorway is actually a repurposed medieval graveslab, giving visitors a tangible connection to the site's layered past.

The second floor served as the castle's main living quarters, complete with the comforts expected by its medieval inhabitants. A fireplace in the eastern wall would have provided warmth, whilst a garderobe in the northeast corner offered private facilities. The room's defensive purpose wasn't forgotten though; narrow, round-headed windows in the west and north walls, along with square openings in the south and east, provided both light and defensive positions. Additional slit openings in the corners allowed archers to cover multiple angles of approach. Wall presses flanking the fireplace and built into the southern wall provided storage for the castle's occupants. This remarkable survival of medieval architecture has been protected under a preservation order since 1947, ensuring future generations can explore this window into Ireland's fortified past.