Viennas 13th and western-most district, Hietzing, was the chicest part of the city and famous for its nightlife back in the 1800s. It is a pleasant and still fashionable leafy suburb of Vienna with splendid villas and gardens, ranging from the Biedermeier summer residences once owned by the 19th century nobility, to the Jugendstil (art nouveau) and modernist town houses favoured by the artists and mercantile classes of late-imperial Vienna. Known as the green district to locals, there is little industry or manufacturing since most local businesses are in banking, insurance or consultancy, including a significant number of international companies. Castle Schnbrunn, once the home of the imperial court and still one of Viennas loveliest attractions, with its huge park and fantastic outdoor swimming pool, is in Hietzing and it is a must during summer. The Lainzer Tiergarten, a former imperial hunting ground, is nowadays Viennas second biggest park after the Prater in Leopoldstadt. The U4 underground line, S3 and S15 trains, and local bus routes link Hietzing with the rest of the city.