The Seto Inland Sea, often shortened to Inland Sea, is the body of water separating Honshū, Shikoku, and Kyūshū, three of the main islands of Japan. It serves as an international waterway, connecting the Pacific Ocean to the Sea of Japan. It connects to Osaka Bay and provides a sea transport link to industrial centers in the Kansai region, including Osaka and Kobe. Before the construction of the Sanyō Main Line, it was the main transportation link between Kansai and Kyūshū.
Yamaguchi, Hiroshima, Okayama, Hyōgo, Osaka, Kagawa, Ehime, Fukuoka, and Ōita prefectures all have coastlines on the Inland Sea; the cities of Hiroshima, Iwakuni, Takamatsu, and Matsuyama are also located on it. The Inland Sea region is known for its moderate climate, with a stable year-round temperature and relatively low rainfall levels: The area is often called "the land of fair weather". The sea is also famous for its periodic red tides caused by dense groupings of certain phytoplankton that result in the death of large numbers of fish.
Since the 1980s, its northern and southern shores have been connected by the three routes of the Honshū-Shikoku Bridge Project, including the Great Seto Bridge, which serves both railroad and automobile traffic.
The International Hydrographic Organization defines the limits of the Inland Sea as follows:
On the West. The Southeastern limit of the Japan Sea [In Shimonoseki-kaikyo. A line running from Nagoya Saki in Kyûsû through the islands of Uma Sima and Muture Simia to Murasaki Hana in Honsyû].
On the East (Kii Suidô). A line running from Takura Saki in Honsyû to Oishi Hana in the island of Awazi, through this island to Sio Saki and on to Oiso Saki in Sikoku.
On the South (Bungo Suidô). A line joining Sada Misaki in Sikoku and Seki Saki in Kyûsyû.
Geographical features :
The Inland Sea is 450 km (280 mi) long from east to west. The width from south to north varies from 15 to 55 km (9.3 to 34 mi). In most places, the water is relatively shallow. The average depth is 37.3 m (122 ft); the greatest depth is 105 m (344 ft).
The Naruto Strait connects the eastern part of the Inland Sea to the Kii Channel, which in turn connects to the Pacific Ocean. The western part of the Inland Sea connects to the Sea of Japan through the Kanmon Straits and to the Pacific through the Bungo Channel.
Major islands :
Major tourist sites :
- Eastern part: Awaji Island, Shōdo Island, Ieshima Islands, Naoshima Islands, Shiwaku Islands
- Central part: Ōmishima, Innoshima, Itsukushima (popularly known as Miyajima), Hinase Islands, Kasaoka Islands
- Western part: Suō-ŌShima, Uwakai Islands, Hashira-jima Islands.
The coastal area of the Inland Sea is one of the most famous tourist destinations in Japan. Even before Japan opened to foreigners in the middle of the 19th century, the sea's beauty was praised and introduced to the Western World
by those who visited Japan, including Philipp Franz von Siebold, and after the country's opening, Ferdinand von Richthofen and Thomas Cook.
Its coastal area, except for Osaka prefecture and a part of Wakayama
prefecture, was appointed the Setonaikai National Park
on March 16, 1934, as one of three oldest national parks in Japan.
, on the island of Itsukushima in the city of Hatsukaichi
, is a UNESCO World Heritage Site and one of the most famous Japanese sites outside Tokyo
. Shodoshima, nicknamed the "island of olives," and the Naruto Whirlpools
are two other well-known tourist sites. Neighboring locations like Kotohira and Okayama are often combined with the tour of the Inland Sea region. Some historic sites, including Yashima in Takamatsu and Kurashiki
, also attract many visitors. Hiroshima is the neighbor city to Itsukushima Shrine and another UNESCO World Heritage Site because of atomic bomb damage in 1945.