A massive infrastructure project is taking shape in the Baltic Sea, connecting Denmark and Germany.

The Fehmarnbelt Tunnel, when completed in 2029, will be the world’s longest road and rail immersed tunnel, spanning 18 kilometers beneath one of the busiest shipping lanes.

A total of 89 prefabricated concrete sections will be placed in a trench on the seafloor, covered, and then linked to create a direct connection between Rødbyhavn in Denmark and Puttgarden in Germany.

The project, costing €7.4 billion, aims to significantly reduce travel times: from 45 minutes by ferry to just 10 minutes by car and seven minutes by train.

Beyond transportation, the tunnel is expected to boost tourism and economic ties between Germany and Scandinavia.

The Fehmarnbelt Tunnel is going to become a transformative project for European infrastructure,business and sustainability.