Situated in the side wing of Clärchens Ballhaus, a dancing venue established in 1913 in Wilhelmine Germany shortly before World War I, there is a hidden gem even unbeknownst to most Berlin inhabitants, a mirrored ballroom (Spiegelsaal) which still captures the spirit of a long-lost era.

This part of the building was badly damaged in World War II—with bullet holes bearing witness to the fierce fighting in the city in 1945 and parts of the ceiling visibly destroyed by Allied bombing prior to this—and it remained in disrepair up until German reunification while the rest of Clärchens Ballhaus was used as music hall, bowling alley and dance venue.

In 2005 the mirror ballroom was re-opened to the public, with the interior largely untouched and unchanged, so that the hall with its chandelier, gallery and decorative stucco at ceilings and walls offers a glimpse at the Golden Twenties in Berlin as a veritable dancing venue and variety hall.

Nowadays the Spiegelsaal is used for regular dining events, sometimes accompanied by operatic performances, literary soirées and private events. Most Sunday evenings, jazz and classical chamber concerts take place in these vestiges of imperial Berlin in a series of Sonntagskonzerten.