Seto Inland Sea

The Seto Inland Sea and the Seto Inland Sea (瀬 戸 内海Japanese Seto Naikai ) is an inland sea, separating the Japanese islands of Honshu, Shikoku and Kyushu from each other. Within the Seto Inland there are many small islands, the largest of which is Awaji -shima in the east.

  • 3.1 Kobe - Awaji - Naruto Expressway
  • 3.2 Seto - Chuo Expressway
  • 3.3 Nishiseto highway / motorway Shimanami



The regulation implementing the Ryokai - hō (领海 法, territorial waters law ') defined in Article 1, the boundaries of the sea as follows:

The Environmental Law Setonai - hō (瀬 戸 内 法) describes in Article 2, paragraph 1 an almost identical extent. The implementing regulation is called for in Article 1, however, a greater extension:

In the first definition, the sea has an area of ​​19,700 km ² and 21,827 km ² of The second one. The maximum water depth is 105 m.


The Seto Inland Sea is divided into the following marine regions:

  • Kii Strait between Honshu and Shikoku
  • Bay of Osaka between Honshu and Awaji -shima
  • Harima - nada (播 磨 滩) between Awaji -shima and Shodoshima
  • Bisan Strait (备 讃 瀬 戸Bisan - seto ) between the prefectures of Okayama and Kagawa Prefecture
  • Bingo - nada (备 后 滩) between the north and the Kasaoka Geiyo Islands
  • Hiuchi - nada (燧 滩) south of it between the Shōnai and the Takanawa Peninsula
  • Aki- nada (安 芸 滩) between the Geiyo and the Boyo Islands
  • Hiroshima Bay north by Aki - nada Geiyo between the islands and Hiroshima
  • Iyo- nada (伊 予 滩) south of Aki- nada between the Yashiro Island ( Suo - Oshima ) the Boyo Islands and the Kunisaki Peninsula
  • Suo - nada (周 防 滩) north of it to the Kammon road

In the larger definition then come added:

  • Bungo Strait between Iyo- nada and Hyūga - nada, ie here the open sea of the Pacific
  • Hibiki - nada (响 滩) north of the Kammon street, between the western coast of Honshu and Genkai- nada, ie the coastal waters of the Sea of ​​Japan before Kyūshū


Are the prefectures of Wakayama, Osaka, Hyōgo, Okayama, Hiroshima and Yamaguchi on the coast of Honshu. On the coast of Kyushu prefectures Fukuoka and Oita. On Shikoku Ehime prefectures, Kagawa and Tokushima bordering the Seto Inland Sea.

The region around the Inland Sea is also called the Setouchi region. Major coastal cities in the region are Kobe, Ube, Hiroshima, Iwakuni, Kurashiki and Matsuyama.


A large part of the lake belongs to the Setonaikai National Park was founded in 1934 as one of the first national parks of Japan. It has a temperate climate with relatively small seasonal variation in low precipitation. In Japan, therefore, this area also "The Land of the nice weather " called (Japanese晴れ の 国hare no kuni ). Most of the more than a thousand islands in the Inland Sea are covered with pine forests. The lake is regularly occurring algal blooms (赤潮Akashio ) is known, a sudden massive proliferation of algae in a water body. Another natural spectacle are the Naruto Whirlpools, arising from the different water depths of the Inland Sea and the Pacific Ocean. Furthermore, there in the Inland one of the last remaining Japanese tidelands, which has not yet been destroyed due to embankments.

The region around the Inland Sea is industrialized. Raw materials can be delivered by ship. The mild climate is favorable for fishing and agriculture.


The islands of Honshu and Shikoku are connected by three bridge systems.

Kobe - Awaji - Naruto Expressway

The easternmost, completed after breaking ground in 1976 in 1998, leads from Akashi ( Hyōgo Prefecture ) on the Akashi - Kaikyo Bridge, the longest suspension bridge in the world, on the island of Awaji -shima, and from there on the Naruto Bridge to Naruto ( Tokushima Prefecture) beyond the 1.3 km wide Naruto Strait. Originally also a train was scheduled, was on the end, however, omitted.

Seto - Chuo Expressway

Built In just ten years, combines Seto Ōhashi since 1988, the Okayama prefecture of Kagawa Prefecture. It consists of a total of six two-story bridges whose respective lower floor is used by the Railway Japan Railways. The Shinkansen does not operate to or on Shikoku.

Nishiseto highway / motorway Shimanami

As the first of the three crossings of the Inland Sea 1975 started but not completed as the last in 1999, combines the Nishiseto highway Onomichi in Hiroshima Prefecture with a total of ten bridges and several smaller islands, on which nevertheless together after all, about 100,000 people live with Imabari in the prefecture Ehime. The bridges are: Shin- Onomichi Bridge, Innoshima Bridge, Ikuchi Bridge, Tatara Bridge, Omishima Bridge, the two Ōshima Bridge and the three Kurushima Kaikyō bridges.