Craggaunowen Castle was built circa1550 by John MacSioda MacNamara, a descendant of Sioda MacNamara, who built Knappogue Castle (1467) which is located only a few miles away. The castle was left in ruins in the 17th century and deemed uninhabitable by the removal of the roof and staircase, and indefensible by removal of the battlements. The Tower House remained a ruin until it was inherited in 1821 by “Honest” Tom Steele, a confederate of Daniel O’Connell.
Steele had the castle rebuilt as a summer house in the 1820s. Following his death in 1848 the lands were divided with Craggaunowen to his niece Maria Studdert.Eventually, having passed through the hands of his descendants, the castle and grounds were acquired by the Irish Land Commission. Much of the poor quality land was given over to forestry and the castle itself was allowed to fall into disrepair. Craggaunowen Castle was restored by John Hunt in the 1960s. Hunt added an extension to the ground floor, which for a while housed part of his collection of antiquities. This collection now resides in the Hunt Museum in Limerick City. Today the castle houses several artifacts from its era as well and is open for visitors to enjoy during the summer months.