On a limestone headland jutting out from the basalt cliffs, with stupendous views of Rathlin Island and Scotland, this castle, now ruined, was built in 1547 by Colla MacDonnell (son of Alexander MacDonnell, lord of Islay and Kintyre, and Catherine, daughter of the lord of Ardnamurchan), then rebuilt in 1555 following an English siege. It was inhabited until the 17th century, when it was abandoned. From the car park, 140 steep steps lead down to the castle.