Hannöversche Südbahn
The Brunswick Southern Railway () was built by the Duchy of Brunswick State Railway as a link from its Brunswick–Bad Harzburg railway to the Hanoverian Southern Railway. It ran through the northwestern Harz Foreland from Börßum via Salzgitter, Ringelheim and Seesen to Kreiensen. It opened on 5 August 1856 and was one of the oldest railways in Germany.