What a unique place to stay!  A boutique hotel built in the former County Prison atop the highest hill in Turku.  It's such an interesting place.  I should say first that I only awarded four stars because I happened to have a very small -- though nicely appointed and functional -- room.  I'm sure I would have given the fifth star if a larger room had been available for me.  (I should say that my bathroom was surprisingly large for a small room).  The hilltop is so interesting.  The best place to watch an 11 p.m. sunset in Turku in June.  A short distance from the hotel is an even more imposing former prison -- now condos, restaurants, and a bar.  It was an amazing area to explore, and although a little bit outside the center of town, the hilltop is actually closer to the castle, maritime museum, ferries, and riverwalk than places more central, all accessible via a fun, free funicular if you choose not to walk down the hill.  Highly recommended.