The tower at the core of the site was built by the Power family, probably in the 16th century. In the 1660s the property came into the hands of the Penn family, and it was during this period that William Penn knew the place. Penn had converted to Quakerism, the Religious Society of Friends, a dissenting movement that rejected formal clergy and emphasised direct, unmediated religious experience, a position that brought its members into repeated conflict with the authorities in both England and Ireland. His later founding of Pennsylvania in 1681 was in part conceived as a refuge where Quakers and others could practise their faith without persecution. That such a figure had a personal connection to a modest tower house in County Cork is the kind of detail that rarely makes it onto monument plaques. The Penn family's association with the Shanagarry property did not end with William himself; his descendants held onto the estate well into the 20th century. To the south of the complex, a stone wall encloses the grounds, likely dating from the 18th century, and the 19th-century house to the west of the tower now stands vacant.