One of my favourite historic Location to visit in Ireland is Ormonde Castle in County Tipperary.
Ormonde Castle description on Wikipedia.
The castle is located on the bank of the river Suir, on the edge of the town of Carrick on Suir, when it was first built the castle would have been set in a large private estate with much land surrounding it.
Today its location is in one of the parks that the town contains.
A summers day visit here is perfect as you can visit the Castle them make use of the park if you bring some lunch with you.
Ireland has such great history that is stored in locations like this, historic buildings are a part of Irish history and offer great attractions to visitors here.
If you are visiting then Ormonde Castle is a great location to put on your list.
Ormonde Castle Gallery