Olivia Charlotte Guinness, Baroness Ardilaun, best known as Lady Ardilaun was, after the British monarch, the richest woman of her time in Britain and Ireland. A daughter of the Earl of Bantry, she was connected to Muckross House, Macroom Castle, the St Anne's Estate in Dublin, and Ashford Castle.

Macroom Castle, in the centre of the town of Macroom, was once residence and fortress of the Lords of Muskerry. The castle has changed owners many times, has been besieged, burned, and rebuilt. The MacCarthys of Muskerry owned it with some interruptions from about 1353 when Muskerry was given to Dermot MacCarthy, 1st Lord of Muskerry, until 1691 when Donogh MacCarthy, 4th Earl of Clancarty lost it definitively.