Hamburg is the principal port of Germany and the second most populous city after Berlin. It was created during the middle ages as a Hanseatic city, that is part of the Hanseatic league of northern port cities stretching from Brugge to Bremen and from Hamburg to Lübeck.
In reality, Hamburg is not located on the sea, but on the delta of the Elbe River: therefore its historic center is crossed by many canals and by two small lakes: the Binnenalster, smaller and more central, and the Aussenalster, larger and further out from the center. Around these two lakes it is possible to bike along bike/pedestrian paths.
In effect Hamburg is a very extensive city and its network of bike paths is also very extensive. Primarily these are bike lanes on the sidewalks along the main roads, such as those adjacent to the Ost-West Strasse which cuts through the center of Hamburg (it has now assumed the name of two German chancellors: Ludwig Erhard Strasse to the west, Willy Brandt Strasse to the east). It is lucky that there are bike lanes because the traffic on this street is really a nightmare!