Carrickkildavnet Castle is a 15th-century tower house associated with the O'Malley Clan, who were once a ruling family of Achill. Grace O' Malley, or Granuaile, the most famous of the O'Malleys, was born on Clare Island around 1530. Her father was the chieftain of the barony of Murrisk. The O'Malleys were a powerful seafaring family, who traded widely. Grace became a fearless leader and gained fame as a sea captain and pirate. She is reputed to have met with Queen Elizabeth I in 1593. She died around 1603 and is buried in the O'Malley family tomb on Clare Island.