In the “Golden Twenties”, Hermannplatz took on a special role not just as a major traffic hub, but also as the most important shopping site in southern Berlin. This was taken into account by the construction of the monumental Karstadt building in 1929: at the time of being erected, with 72,000 m² of space spread over nine floors in total (two of which were underground), the building was the largest department store in continental Europe. The height and overbuilding went far beyond that usual in Berlin at the time. At the same time, the building was also the first modern department store to be equipped with some 24 moving staircases, 24 lifts for carrying people, 13 service lifts and eight goods lifts. It also achieved fame above and beyond this as the first department store to feature its own underground entrance. Karstadt on Hermannplatz rapidly developed far beyond the city limits to become an attraction. As well as a wide range of different products, it offered guests numerous services including a swimming area, hairdressing salons, a sports hall and a number of different restaurants, with something to suit every pocket and taste. It even offered cultural events.
As a result, Karstadt became much more than a traditional shopping location, and was a much sought-after day-trip destination in its own right for a highly diverse clientele. The main attraction was undoubtedly the roof garden, which, with bands playing daily and views over Kreuzberg and Neukölln and beyond from a height of 32 metres, offered a unique ambience. With its attractiveness as a location for new experiences and lived diversity, Karstadt on Hermannplatz was without doubt a mirror for society, as it established itself as a place for the locals and their visitors.