Renovated castle on the edge of Baden, a town about 40km from Vienna. Atmospheric, high quality, with an additional health spa with usage of pool, sauna, steam room, gym, the lot.
Continental breakfast included (lunch/dinner extra), beautiful surroundings, helpful staff.
Very relaxing and with good train connections to Vienna, other cities, Viennese mountains, etc.
However, the train station is over a mile's walk through the town of Baden, which seems a quiet town full of 50yr+ couples and retired people. If you don't have a car, you may find it a little isolated.