Through the
Middle Ages, Clare Island was part of the lands of the O'Malley family. The ruins of an O'Malley tower-house, known as
Granuaile's Castle because of its most famous resident, are close to the pier at the eastern edge of the island.
Clare Island Abbey near the south coast of the island was founded by the O'Malleys and contains the O'Malley Tomb, a possible burial site of
Gráinne O'Malley. The Abbey is known for its rare medieval roof paintings. In 1588, a ship from the
Spanish Armada was wrecked on Clare Island and its men were killed by the O'Malleys. A very prominent landmark of the island is the Clare Island
Lighthouse, established by John Denis Browne, the
1st Marquess of Sligo, in 1806. On 29 September 1813 a fire, caused by careless disposal of the oil-lamp wicks, destroyed part of the tower and the lantern. The rebuilt light was ready in 1818. In 1834, the tower was struck by lightning. The lighthouse was decommissioned on 28 September 1965, replaced by the modern
Achillbeg Island lighthouse on the south side of
Achill Island. Clare Island Lighthouse has been refurbished and is now an upmarket guesthouse, while its optic is on permanent rotating display at the
World of Glass museum and visitor centre in North West England.
Demographics The table below reports data on Clare Island's population taken from
Discover the Islands of Ireland (Alex Ritsema, Collins Press, 1999) and the
Census of Ireland. ==Fauna and flora==