World's Longest Tunnel Under Construction Between Denmark and Germany

An 18-kilometer-long tunnel is under construction beneath the Baltic Sea between Denmark and Germany, set to become the world's longest combined road and rail tunnel. Known as the Fehmarnbelt Tunnel, it is expected to be completed by 2029.

The tunnel is being built 40 meters below the Baltic Sea, connecting Denmark’s Lolland Island with Germany’s Fehmarn Island. Once completed, it will significantly reduce travel time between the two countries—cutting it down from 45 minutes by ferry to just 10 minutes by car and 7 minutes by train.

This is one of Europe’s largest infrastructure projects, with an estimated cost of approximately €7 billion. The tunnel will enhance connectivity between Scandinavia and Central Europe, boosting both trade and travel.

The construction involves assembling 79 large and 10 smaller tunnel sections, which are being immersed and joined together under the sea. Advanced high-tech safety systems are being installed to ensure emergency preparedness within the tunnel.

Before this tunnel, ferries were the only means of transport across the Baltic Sea in this region. Once completed, the Fehmarnbelt Tunnel will revolutionize the way people and goods move across Denmark and Germany.