The Hamburg-Altona link line is a railway line in Hamburg, Germany. Nowadays, it connects the lines from the north and northwest of Hamburg and Altona station with Hamburg Hauptbahnhof and the lines to the southwest, south and east. Initially designed as a freight line only, it is now one of the busiest lines in Germany. It includes the suburban tracks of the Hamburg Stadtbahn, originally the core of the Hamburg S-Bahn.

The Wallring is a semi-circular urban ensemble encircling the inner city of Hamburg. It consists of a four-lane ring road with a total length of 3.3 kilometers (2.1 mi) and a continuous built-up street front on its inner side. The outer perimeter is – for the largest part – made up by a string of parks.