The "Sofiensaal" may the best known "forgotten place" in Vienna. It was heavily used for various events and well-known for its excellent acoustics. Decca even adapted the hall in the 1950s as it primary European recording studio. In 2001 the hall accidentally burned down during careless adaption work for a conference center.
The hall is a registered Austrian landmark so the proprietor was not allowed to pull down the ruin completely. In 2006, the remains were sold to a company which is partly owned by the town and it was promised to rebuild this former Biedermeier jewel as the core of a new and modern building.
Rebuilding started ~2 years ago. First the walls were protected against the weather and the collapsed roof was put away, revealing the first designation of this house: a steam bath with a large swimming pool in the center!
This explains the excellent acoustics. The whole hall was built like an instrument with a large resonating cavity below the floor. You can imagine the extents in the panorama, displayed by the bricks that have been accurately vacated and hopefully will stay visible in the future.