Vienna’s sixth district hosts high street shopping heaven and pedestrian area Mariahilfer Strasse. The weirdest local building is probably the city aquarium Haus des Meeres, housed in one of Vienna’s six remaining World War II defense towers, and topped with a rooftop bar that offers stunning views over Vienna and the center. One of the most historic sites in the area is the passageway of 18th century Raimundhof with its small shops and cafés. It leads from Mariahilfer Strasse to Windmühlgasse. For a glimpse into the world of early 19th century theater, visit Semperdepot, the former depository for theater decoration, which now hosts art exhibitions and fairs.