Johnstown Castle lies a short drive south-west of Wexford Town, set in ornamental grounds with lakes, towers, and the slightly theatrical confidence of a nineteenth-century Gothic Revival estate. It is one of the easiest day outings from town if you have a car.
The estate also houses the Irish Agricultural Museum, which is more interesting than the name suggests if you want to understand rural southeast Ireland. Pair the castle with the Irish National Heritage Park only if you have a full day; otherwise choose one and do it properly.