 The traffic routing was not only influenced by the location of the already existing stations the line was supposed to connect, but also by land availability in the city centre. One of the original drafts, which called for building the line along Leipziger Straße, had to be scrapped because of overly high land prices. The moat of the 17th century Berlin Fortress was filled up between Hackescher Markt and Jannowitzbrücke stations and, since it was public land, was used for building the railway line. This explains some of the curvy sections on the Stadtbahn, especially between Alexanderplatz and Jannowitzbrücke stations.
