Until 1954, Drimnagh Castle was Ireland’s oldest continuously inhabited castle, and it’s still the only one with a flooded moat. A fine example of a Norman feudal castle, it has other assets, including a restored great hall, a medieval undercroft, an embattled tower and a folly tower. Don’t miss the 17th-century formal gardens, which come complete with boxed hedges and lollipop trees. The castle is open to visitors all year. It was restored in 1986.