Spa Modernisms. Spa architecture is often associated with representative buildings of the so called Golden Age, the late 18th and 19th century, when the spa town as a distinct architectural ensemble developed throughout Europe. The sources and wells, grand hotels, theatres and casinos in (neo)classic style shape the common vision. A no less important, if currently less popular, heritage of European spa culture are its modernist buildings and facilities, including bathhouses, hotels or works of art.