Some hotels are hundreds of years old and very quaint. They do have modern plumbing, though.
Among the best places to stay in Spain are the centuries-old Paradores.
http://www.paradores-spain.com/
All have been restored, with modern facilities
False. In Spain, there are a wide variety of hotels, ranging from historic buildings to modern structures. To determine whether a specific hotel is new and modern or not, you can look up information about the hotel online. Hotel websites often provide photos and descriptions, which will give you a good idea of the style and age of the building. Additionally, travel review websites like TripAdvisor or Booking.com often feature reviews and photos from previous guests, allowing you to get a sense of the hotel's condition and style.