Granuaile's Castle

Granuaile's Castle is a tower house on Clare Island that rises prominently on the east coast, overlooking the Atlantic Ocean. The structure stands roughly 40 feet high and features two corner turrets that served defensive purposes.

The O'Malley clan built this fortress in the 1500s as a stronghold for controlling their sea and land power. In 1831 it was converted into a police barracks, marking a significant change in its purpose.

The fortress is closely linked to Grace O'Malley, a remarkable woman who controlled Irish waters in the 1500s. Visitors can still sense her presence and influence through the structure of this stronghold built by her family.

The castle is reached by ferry from Roonagh Pier to Clare Island, with the crossing taking around 15 minutes. Spring and summer offer better conditions for visiting, as weather is more stable and more services are available on the island.

When the castle became a police barracks in 1831, purple slate was added to its defensive towers, an unexpected detail that links its military past to its later role. This material remains visible today and shows how the building changed over time.

Location: County Mayo

GPS coordinates: 53.79975,-9.95131

Latest update: December 8, 2025 19:50