The Sofiensaal is a concert hall and recording venue in the third district of Vienna. It was originally built as a steam bath and opened in 1826. After being transformed into a concert hall, Johann Strauss (father and son) used to perform here. There is also a dark side to this venue. In 1926 the Austrian branch of the NSDAP was founded here. During the Nazi regime it served as a detention center for Jews. They were forced to the extermination and concentration camps from here. The Sofiensaal burned down on 16 August 2001, but was rebuilt and opened once again in December 2013.