The Kanmon Straits separate Shimonoseki City (Yamaguchi Prefecture on mainland Honshu) and Moji-ku, Kitakyushu (Fukuoka, Kyushu).

The name “関門 Kanmon” Straits is taken from the names of both areas; the Kanji character “関 Kan” from Shimonoseki City (下関) and “門 Mon” from Moji-ku (門司区).

The Kanmon Straits are a narrow marine corridor that looks like a river. Due to its narrow curvy nature and rapidly changing currents, it is said to be a “most difficult point to navigate”.

According to the “Territorial Waters Act (Act on the Territorial Sea and the Contiguous Zone)”, this is one of starting points of the Seto Inland Sea. More precisely, as the map below indicates, it is defined as the east side of the Kanmon Straits.

This means the Kanmon Straits is the “most westerly starting point” of the Seto Inland Sea!

The image below is the view looking down the Kanmon Straits from the site of Kyushu’s Moji Castle.

The water to the left of Kanmon Bridge is the Seto Inland Sea’s Kanmon Straits, while the mass of water in which islands appear to be floating is the Hibiki Sea (not part of the Seto Inland Sea).

The Seto Inland Sea begins with these Straits.

Taken from a wharf in Yamaguchi prefecture, the image below is of the Kanmon Straits and Kanmon Bridge before dawn.

Connecting to an expressway and built over “Hayatomo Seto”, the narrowest part of the Kanmon Straits, Kanmon Bridge was the longest in Japan as well as East Asia when it opened in 1973 at a length of 1,068 m.

Due to their geographic location, the Kanmon Straits are a hugely important artery that connects overseas ports with major Japanese ones.

All day long, huge tankers and cargo ships come and go constantly. On the busiest days, more than 700 vessels pass through!

The sound of the Straits and of the ships’ whistles are one of the “100 best soundscapes in Japan”.

This  soundscape is best experienced early in the morning before the roads get busy and drown out the sound of waves hitting the wharf, and the ships’ whistles echoing across the Straits.

Even in the early morning, tankers and cargo ships are constantly on the move. As the swarms of fishing boats that set off at dawn join them, it all starts to get quite noisy! Despite the number of vessels, things stay remarkably organized with a minimum of problems.

The Kanmon Straits are one of the most difficult to navigate. Each “Mizusaki-nin” (maritime pilots), whose job it is to keep marine transportation safe, is required to pass a national examination and hold a professional certificate. If a ship weighs 1 ton or, a pilot will board to support its maneuvers through the Straits.

“Tooooooot”, the bass horns of passing ships are full of atmosphere…

Surprisingly, the Kanmon Straits is a popular spot for foreigners to visit. They say it is rare to be able to watch big ships pass by so close.

By the way, some very important historic events occurred here! It is the “site of the battle of Dan-no-ura” where the final Gempei showdown broke out in 1185, and also where the “Shimonoseki Campaign” occured, a war between the Japanese feudal domain of Chōshu and 4-powerful regions.

By the way, the best time of year to see the sunrise is from spring to summer. (The sun rises on the Kyushu side and moves south (right) from autumn to winter).

Though you can’t always see the sun rise over the horizon, you can listen to the soundscape of Dan-no-ura as the sky starts to glow in the early morning light anytime.

The Kanmon Straits are located at the most westerly point of the Seto Inland Sea. They are most important for maritime transportation with lots of ships coming and going. It is also the location of hugely significant historical events that shaped Japan. And now, it is famous for viewing the massive Kanmon Bridge.

Would you like to visit the place where the Seto Inland Sea begins?

Location: 1-27 Dan-no-ura chō, Shimonoseki-shi, Yamaguchi

Website (Japanese) : http://www.kanmon.gr.jp/

Setouchi Finder Photo-writer : Hironobu Matsuoka