The monumental spa building was built in Early Historicism style between the years 1864 and 1866 according to the design of architects L. Renner, Gustav Hain and Eduard Labitzky behind the present-day Mill Colonnade in the spa centre of Karlovy Vary. The grand opening of the new spa house, known as Lázně III (Spa III) since the foundation of Czechoslovakia, took place on 10 September 1866.
At the time of its completion, the new spa building provided most contemporary balneological procedures and it also functioned as a music centre. The complex included steam baths, a concert hall named in honour of Antonín Dvořák, four small halls, and a restaurant.
During the reconstruction of the roof in 2002, an extensive fire broke out in the attic, completely destroying the roof truss over the concert hall. The costly renovation of the building was completed in 2004. The spa building continues to serve not only for traditional spa treatment complemented with modern balneological procedures, but also as an important cultural and social centre. The Antonín Dvořák Concert Hall, for example, regularly hosts concerts of the Karlovy Vary Symphony Orchestra.
The story of the Windsor complex, known under the name Spa III, dates back to the 19th century.
The spa building, in English Gothic Revival style, was erected in 1866 according to the design of builders L Renner, Gustav Hain and Eduard Labitzky.
The Kurhaus, as it was known, was one of the most modern balneological institutes in Austria-Hungary. Spa III provided most of the treatment procedures offered at the time, and also fulfilled a role as spa music centre.
During the Second World War, part of Spa III’s ground floor was rebuilt for the needs of the Imperial City Hospital. Only minor maintenance work was undertaken on the building following the end of the war.
In 1951, the Central Health Institute of Czechoslovakian spas and hot springs was located in the Spa III building, and extensive renovation took place on the building between 1956 and 1959.
Spa III is today protected by the law for its structural, historic and cultural importance..
Between 2013 and 2014, the Windsor complex underwent complete renovation.