Schönhauser Allee
It was extended to Alexanderplatz by July 1913, with the Wilhelmplatz–Alexanderplatz route swiftly becoming the most heavily traveled of the Berlin U-Bahn. Three-and-a-half weeks later, on 27 July 1913, the northern extension to the S-Bahn station (Schönhauser Allee), which was originally called Nordring was also opened. Construction also began in March 1910.