If completed, the underwater passage would span 190 kilometers, dwarfing the current longest tunnel in the world, the 68-kilometer section of the Chengdu metro, and the 38km Channel Tunnel, which ...

After two years of underwater testing and 56,000 interviews with Dover-to-Calais travelers, a combined group of English, French and U.S. engineers and economists prepared to announce, in a ...

The Seikan in Japan is an “awe-inspiring” underwater tunnel that runs for 33.46 miles. There's also the Channel Tunnel that connects UK and France - which is also long at 31.4 miles. More in World ...