Ross Castle 

Ross Castle sits on the edge of Killarney's lower lake and was built by O'Donoghue Mór in the 15th century. The Castle came into the hands of the Brownes who became the Earls of Kenmare and owned an extensive portion of the lands that are now part of Killarney National Park . Legend has it that O'Donoghue still exists in a deep slumber under the waters of Lough Leane.