Japan boasts the world's longest underwater tunnel, which stretches for more than miles under the seabed of the Tsugaru Strait, but it's now barely being used. Work on the Seikan Tunnel was ...

Seikan Tunnel stretches 53.9 km and stands as Japan's longest tunnel. It is located beneath the Tsugaru Strait and connects the islands of Honshu and Hokkaido ...

Despite being the longest train tunnel in the world, alternatives like the Seikan Tunnel in Japan's Tsugaru Strait and the Channel Tunnel connecting the UK and France offer quicker routes.

When it officially opens, the Gotthard will surpass Japan's 53.9-kilometre Seikan tunnel as the world's longest train tunnel. The 50.5-kilometre Channel Tunnel that links England and France will ...