after the norman invasion of ireland, the land around the lakes was owned by the mccarthys and o'donoghues. ross castle is a 15th-century tower house on the shore of lough leane. it was once the residence of the chieftain o'donoghue mór. the castle was extended in the 17th century. it has been restored and is open to the public. a 1580s elizabethan military record describes the killarney area as a meagrely inhabited wilderness of forest and mountains.