![Old Elbe tunnel](https://on-historic-routes.com/loglog/wp-content/uploads/Elbtunnel02-150x150.jpg)
The Elbe estuary in Hamburg is a natural obstacle for modern land-bound traffic. Yet the harbor made Hamburg into a traditional trading city. The old Elbe tunnel is part of both, the harbor and the means to cross the river. It is a hidden gem of industrial heritage in the vibrant city. 19th century …