Birr Castle.
The castle is home to the Parsons family, and has been since the early 1600's -- Birr, in fact, has also been called "Parsonstown".  It is one of the few remaining "big houses" of the Irish Ascendancy, and is not generally open to public visiting, since it is still a private residence.
The castle has 88 rooms, the same as the number of keys on a piano keyboard and the number of constellations in the sky.