It's a converted 19th century prison, and yet it's well apportioned.
The only real complaint I had was that the hotel does not have air conditioning, and of course we visited in June. They provided a fan, however, which was great, but there were 4 of us in one room and only one fan, so some people had to swelter.
That said, it's a fun experience to take the family, and of course Lucerne is a great town to explore!