There are few castles anywhere in Ireland that can boast such a dreamlike enchanted setting as this ruined tower house on the shore of Killarney's Lower Lake. Built in the late 15th century, it is fairly typical of its type, with square bartizans on diagonally opposite corners and a thick end wall containing a tier of chambers and a winding mural stair. The tower stands within a square bawn defended by round corner towers, two of which survive, the others having been removed in 1688 to make room for an extension, the ruins of which remain on the south side of the castle.The castle was the chief seat of the O'Donaghue Mors, hereditary rulers of this district and descendants of the ancient kings of Munster. After the Desmond rebellion, their fortified lands were acquired by the MacCarthy Mors and later Sir Valentine Browne, ancestor of the Earls of Kenmare. In 1652 the castle was held by Lord Muskerry against a Cromwellian force of 1,500 foot and 700 horse soldiers. It fell after floating batteries were brought over land to bombard it from the lough as well as from the land. The Brownes, who retained the old faith, remained in the castle until they lost their estates in 1690 for supporting the Jacobite cause. Although their lands were recovered around 1720, they were unable to regain possession of the castle, which had been taken over as a military barracks.