World's Most Extreme - Season 1 - Eps 6: Tunnels
From the Swiss Alps to a Japanese metropolis, tunnels are often wonders of modern construction, but can also be scenes of disaster. These are the 10 most extreme tunnels on Earth.
About World's Most Extreme

Title: World's Most Extreme
First Air Date: 2014-09-02
Last Air Date: 2018-12-10
Status: Ended
Rating: 4/10 (from 1 votes)
Language: EN
Seasons: 2
Total Episodes: 12
Network: Travel Channel More4
Genres: Documentary
Production Companies: Arrow Media
Synopsis
World's Most Extreme takes you to the most jaw-dropping and extreme places anywhere in the world.