O'Brien's Castle Travel Guide

O'Brien's Castle, also known as Furmina Castle or Caisleán Uí Bhriain in Irish, stands as a striking ruin on Inisheer, the smallest of the Aran Islands. This 15th-century tower house was strategically constructed by the Clann Teige, a branch of the powerful O'Brien family, atop Dún Formna, an ancient ringfort dating back to between 500 BC and 100 AD. The location was chosen for its commanding views of Galway Bay and the mainland, allowing control of shipping routes and serving as a stronghold.The castle's history is marked by conflict. In 1582, it was seized by the O'Flahertys of Connemara, rivals of the O'Briens. In 1652, during the Cromwellian conquest of Ireland, Oliver Cromwell's army captured and deliberately damaged the castle to prevent its further use as a fortification. Since then, it has remained a ruin, a testament to the turbulent times.Today, O'Brien's Castle is a National Monument of Ireland. Visitors can explore the remains of the rectangular donjon (keep), which once had four stories. The original entrance was on the first floor, accessed by an external wooden stairs. The first floor served as a great hall, with mural stairs leading to the parapet. The ground floor was a basement with three vaulted chambers. Look for the corbel of a bartizan (a small projecting turret) with a human face carved into it. From the castle, enjoy panoramic views of Inisheer, the other Aran Islands, the Clare coast, and the Cliffs of Moher.