This rugged medieval castle, surrounded entirely by water, dates from the 15th century. Its name comes from the Gaelic Carragain Phoill (or “Rock of the Hole”), and probably describes its location in the channel between the land and Carrig Island. It was once the seat of the O’Connor clan, who ruled most of the Kerry clan for a century or so—it was besieged by English forces in the late 16th century and taken again by Cromwell less than a century later. Although it’s a ruin, the tower is almost as tall as that of Blarney Castle. One wall is new, however—modern safety regulations wouldn’t allow access to the upper part of the tower without it. Still, it blends in well, and it does mean that you can climb all 104 steps to the top to see the magnificent views.