Amazing world of tunnels

Learn more about tunnels that are indispensable to our lives!

The Top Longest and Deepest Tunnels
in Japan and Around the World!

Here are tunnels ranked No.1 in various fields around the world.
You will find that Japan's tunnel technology is very advanced, even from a global perspective.
How many of these tunnels do you know?

The longest railway tunnel
in Japan
Seikan Tunnel (Aomori Prefecture - Hokkaido)


The Seikan Tunnel is an undersea tunnel that crosses the Tsugaru Strait and connects the mainland and the northern island of Hokkaido. It opened in 1988 as a conventional Kaikyo Line, and the Hokkaido Shinkansen has been running on it since 2016. It is the second longest railway tunnel in the world.

The world's first
undersea railroad tunnel
Kanmon Railway Tunnel (Yamaguchi Prefecture - Fukuoka Prefecture)

Opened in 1942 (down line)
and 1944(up line)

Connecting Shimonoseki Station and Moji Station on the Sanyo Main Line, the down line opened in 1942 and the up line in 1944. The upper and lower lines were built separately for ease of construction and as a precaution against accidents. The length of the tunnel running underneath the sea is about 1,140 meters for both up and down lines.

The longest railway tunnel
in the world
Gotthard Base Tunnel (Switzerland)


The Gotthard Base Tunnel, the longest railway tunnel in the world, was completed in 2016 and runs through the Swiss Alps. The construction period was 17 years, and the total construction cost was about 1.3 trillion yen (118 billion USD assuming 110 yen to the dollar).

The longest road tunnel
in Japan
Yamate Tunnel (Tokyo)


The Yamate Tunnel, which opened to traffic in 2015, is located on the west side of the Central Circular Route of the Metropolitan Expressway (Wangan Line to Ikebukuro Line) and runs deep underground. It is the second longest road tunnel in the world.

The world's longest undersea road tunnel Tokyo Bay Aqua-Line (Kanagawa Prefecture - Chiba Prefecture)


Opened in 1997, the undersea tunnel is 9.5 km long on the Kawasaki side of the expressway which crosses Tokyo Bay between Kawasaki City and Kisarazu City. It was built with the world's largest (at the time of construction) shield machine (tunnel boring machine) with an outer diameter of about 14 meters.

The longest road tunnel in the world Laerdal Tunnel (Norway)


The Laerdal Tunnel in western Norway is the longest road tunnel in the world. It takes about 20 minutes to pass through the tunnel. Brightly colored lights placed every six kilometers help drivers stay alert. There is also a rest area where weddings can be held.

The longest mountain road tunnel in Japan Kan-etsu Tunnel (Gunma Prefecture - Niigata Prefecture)


The Kan-etsu Tunnel is located on the border between Gunma and Niigata prefectures. It runs through Mt. Tanigawa which has an altitude of about 2,000 meters. The down line opened in 1985 and the up line in 1991, changing the lifestyle of this snowy region.

The deepest station in Japan Doai Station, Joetsu Line (Gunma Prefecture)


Doai Station, at the foot of Mt. Tanigawa, is an unmanned station nicknamed mogura (=a mole) station. The platform for the down line is located deep underground in the Shin-Shimizu Tunnel, and the stairs are 338 meters long with 462 steps. It takes about 10 minutes to walk down to the platform.

The longest undersea tunnel in the world Channel Tunnel (England - France)

Undersea section is 37.9km

The Channel Tunnel, also known as the Eurotunnel, connects the United Kingdom and France through the Strait of Dover. It opened in 1994. In addition to the international train Eurostar, car trains run there to transport you in your car or bus.
※ The photo above shows the interior of the car train (as of April 2020).

(as of April 2020)