Denmark and Germany will soon be linked by the world's longest underwater tunnel, which will extend up to 40 meters below the surface of the Baltic Sea.
As per CNN, this monumental structure is set to open in 2029.
The Fehmarnbelt Tunnel, 18 kilometers (11.1 miles) long, will significantly reduce travel time between the two countries.
The first tunnel element was inaugurated on June 17 by King Frederik X of Denmark.
Construction began in 2020 after more than a decade of planning.
The tunnel will run between the German island of Fehmarn and the Danish island of Lolland, offering an alternative to the current ferry service.
Travel time will be reduced from 45 minutes by ferry to 7 minutes by train and 10 minutes by car.
Meanwhile, the tunnel will include two double-lane motorways and two electrified rail tracks.
It will shorten train journeys from Copenhagen to Hamburg to 2.5 hours and cut car travel time by about an hour.
However, it will also create a shorter land route for freight between Sweden and Central Europe.
Construction, costing over 7 billion euros ($7.1 billion), involves a large factory in Denmark building 89 massive concrete sections.
These sections will be placed just beneath the seabed and moved into position over three years.
The project, initiated by a 2008 treaty between Germany and Denmark, faced legal challenges in Germany over environmental concerns and competition but was approved by a federal court in 2020.
The tunnel is expected to benefit businesses and reduce environmental impact by encouraging train travel over air and road transport.
Additionally, new natural areas and stone reefs will be created as part of the project, promoting environmental conservation.