is a Japanese

national park A national park is a nature park, natural park in use for conservation (ethic), conservation purposes, created and protected by national governments. Often it is a reserve of natural, semi-natural, or developed land that a sovereign state dec ...

, comprising areas of

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

Seto Inland Sea The , sometimes shortened to the Inland Sea, is the body of water separating Honshū, Shikoku, and Kyūshū, three of the four main islands of Japan. It serves as a waterway connecting the Pacific Ocean to the Sea of Japan. It connects to Osaka ...

, and of ten bordering

prefectures A prefecture (from the Latin ''Praefectura'') is an administrative jurisdiction traditionally governed by an appointed prefect. This can be a regional or local government subdivision in various countries, or a subdivision in certain international ...

. Designated a national park in 1934, it has since been expanded several times. It contains about 3,000 islands, known as the Setouchi Islands, including the well-known

Itsukushima is an island in the western part of the Inland Sea of Japan, located in the northwest of Hiroshima Bay. It is popularly known as , which in Japanese means "Shrine Island". The island is one of Hayashi Gahō's Three Views of Japan specified in ...

. As the park encompasses many non-contiguous areas, and covers a tiny proportion of the Inland Sea's total extent, control and protection is problematic; much of the wider area is heavily industrialized.

History

In 1934, when the area was envisioned as Japan’s first national park, it was far smaller than the expanse of today. Sixteen years later, in 1950, an expansion would seek to include other iconic sites in the region, bringing the total area roughly up to that of the present-day. Setonaikai is the biggest national park in Japan. In 1996,

Itsukushima Shrine is a Shinto jinja (shrine), shrine on the island of Itsukushima (popularly known as Miyajima, Hiroshima, Miyajima), best known for its "floating" ''torii'' gate.Louis-Frédéric, Nussbaum, Louis-Frédéric (2005)"''Itsukushima-jinja''"in ''Japa ...

(in Hiroshima prefecture) was registered as a “cultural site of world heritage” by UNESCO. It is known as one of the top three “most scenic spots” in Japan. In the 1960s and 1970s, a period of rapid economic growth was fueled in Japan, resulting in industrial contamination of the surrounding environment. In both fresh and ocean waters, unmonitored chemical runoff led to reduced water quality, mainly due to area farms’ use of synthetic fertilizers, pesticides, and herbicides. Detrimental levels of heavy metals began to rise, gradually affecting the natural food chain and greater ecosystem. Starting in the 1980s (and continuing on into the present day), water quality has been drastically improved; stricter regulations on chemical use and runoff would be enforced, as well as advancements in technology, namely a high-performance sewage disposal.

Climate

Setonaikai National Park maintains relatively mild temperatures throughout the year, so the climate is sometimes referred to as “Mediterranean”; in essence, the average temperature in winter rarely dips below freezing, or above 90°F (around 30°C) in the summer.

Sites

There are numerous sightseeing places in the national park. Kanmon Strait is one of them. It is between Honshu and Kyushu. A suspension bridge called

Kanmon Bridge The (Asian Highway Network ) is a suspension bridge crossing the Kanmon Straits, a stretch of water separating two of Japan's four main islands. On the Honshū side of the bridge is Shimonoseki (, which contributed ''Kan'' to the name of the s ...

spans the strait. In 1973, when it was opened for the public, it was the longest bridge (0.66 miles) in Asia. The

Naruto whirlpools The are tidal whirlpools in the Naruto Strait, a channel between Naruto in Tokushima and Awaji Island in Hyōgo, Japan. The strait between Naruto and Awaji island has a width of about . The strait is one of the connections between the Paci ...

in Tokushima prefecture are tidal whirlpools in the Naruto Strait, a channel between Naruto and Awaji Island in Hyogo prefecture. The whirlpools, one of the prefecture’s major tourist attractions, are formed due to a narrow width (0.8 miles) of the strait and a water level of 5.6 feet between the Inland Sea and the Open Sea caused by the ebb and flow of the tide. It sometimes creates a whirlpool 100 feet in diameter.

Facilities

There are facilities where people can experience and learn about nature in the park. Mt. Rokko Nature Conservation Center and Mt. Rokko Guide House in Hyogo prefecture are places where people can find natural specimens of Mt. Rokko. Wasuzan Business Center is in Okayama prefecture. It stands on the top of Washuzan Mountain. It is near Seto-ohashi Bridge which is a series of ten bridges between Okayama and Kagawa prefectures. The total length is 8.1 miles (13.1 km). From the center, people can see the panorama of the bridge and the Inland Sea. It is possible to learn about the nature around the bridge and the history of the Inland Sea.”Facilities - Setonaikai National Park” Ministry of the Environment, 1 February 2012.

Natural areas

Islands An island (or isle) is an isolated piece of habitat that is surrounded by a dramatically different habitat, such as water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An island ...

: Awaji Island (part),

Bōyo Islands The are a group of 41 islands that belong to Yamaguchi Prefecture, Yamaguchi and Ehime Prefectures in the Seto Inland Sea, Inland Sea. The largest by far is Suō-Ōshima, or Yashiro Island. List of islands The islands are categorized into the f ...

, Ieshima,

Miyajima may refer to: Places * Miyajima, another name for the Japanese island Itsukushima * Miyajima, Hiroshima, a former town on this island, merged into Hatsukaichi, Hiroshima is a city located in Hiroshima Prefecture, Japan. The name derives from a m ...

Naoshima is an island in Japan's Seto Inland Sea, part of Kagawa Prefecture. The island is best known for its many contemporary art installations and museums. The administers Naoshima and 26 smaller islands nearby. As of 2020, the town has an estimated ...

Shiwaku Islands The or are an archipelago in the Seto Inland Sea, between the larger Japanese islands of Honshu and Shikoku. The group is situated between Okayama Prefecture and Kagawa Prefecture in the western Bisan Seto and consists of 28 islands of various ...

Shōdoshima Shōdoshima or is an island located in the Seto Inland Sea, Inland Sea of Japan. The name means "Island of Azuki bean, Small Beans". There are two towns on the island: Tonoshō, Kagawa, Tonoshō and Shodoshima, Kagawa, Shōdoshima, composing the ...

Tomogashima is a cluster of four islands in the Inland Sea, off Wakayama, Wakayama, Japan. The four islands are , , , and . The islands form part of the Setonaikai National Park. History The islands were used by Buddhist monks for Shugendō. The folklore o ...

Mountains A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher th ...

Mount Rokkō is the name of a range of mountains in southeastern Hyōgo Prefecture, Japan. Outline There is no single mountain or peak called "Rokkō," although the highest peak of the mountains is called , (literally, ''the highest peak of the Rokkō ...

Mount Maya is a mountain in Kobe, Hyōgo Prefecture, Japan. This mountain is one of the major peaks of the Rokkō Mountains, and is the most popular peak for visitors on the West-Rokkō Mountains. Outline Mount Maya is one of the two centers in Rokk ...

Mount Noro is one of the most popular mountains around Hiroshima, Japan. It is part of the Setonaikai National Park. Mount Misen is famous for mountain climbing, trekking, camping and sakura, camellia, hydrangea ''Hydrangea'', () commonly named th ...

Straits A strait is an oceanic landform connecting two seas or two other large areas of water. The surface water generally flows at the same elevation on both sides and through the strait in either direction. Most commonly, it is a narrow ocean channe ...

Akashi Strait The is a strait between the Japanese islands of Honshu and Awaji. The strait connects Seto Inland Sea and Osaka Bay. The width of the Akashi Strait is approximately 4 kilometers, and maximum depth is about 110 meters. The fastest tidal current ...

Hōyo Strait The is the strait at the narrowest part of the Bungo Channel in Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the wes ...

Kitan Strait The or separates Awaji Island from Wakayama, Wakayama Prefecture, Japan and connects the Osaka Bay in the north to the Kii Channel in the south. The total width is 11 km, but the islands of Tomogashima reduce the distance to be spanned by ...

Naruto Strait is a strait between Awaji Island and Shikoku in Japan. It connects Harima Nada, the eastern part of the Inland Sea and the Kii Channel. A famous feature of the strait is the Naruto whirlpools. Ōnaruto Bridge, the southern part of the Kobe-A ...

Kanmon Straits The or the Straits of Shimonoseki is the stretch of water separating Honshu and Kyushu, two of Japan's four main islands. On the Honshu side of the strait is Shimonoseki (, which contributed "Kan" () to the name of the strait) and on the Kyushu ...

* Other:

Cultural sites

* Shrines: Itsukushima Jinja,

Kotohira-gū (also known as , , or Konpira Shrine in English) is a Shinto shrine in the town of Kotohira in Kagawa, Japan. This shrine is patron of sea ship transport and sailors. Located at halfway to the top of Mount Zōzu, the shrine stands at the en ...

Mekari Shrine is a Shinto shrine located in Moji-ku, Kitakyūshū, Fukuoka, Japan. History The wife of Emperor Chūai, Empress Jingū, came here sometime during the legendary military invasion of Korea in the 3rd century. She had Mekari Shrine built as a wa ...

Temples A temple (from the Latin ) is a building reserved for spiritual rituals and activities such as prayer and sacrifice. Religions which erect temples include Christianity (whose temples are typically called churches), Hinduism (whose temples ...

Futago-ji is a Tendai Buddhist temple in Kunisaki, Ōita Prefecture, Japan. It is located on the slopes of Mount Futago, the highest mountain on the Kunisaki Peninsula. The temple was established in 718 by Ninmon and became the central temple of Rokugō- ...

Yashima-ji is a Shingon temple in Yashima, a lava plateau to the northeast of Takamatsu, Kagawa Prefecture, Japan. A branch temple of Ninna-ji in Kyoto, it is the eighty-fourth temple on the Shikoku 88 temple pilgrimage. It is said to have been founded a ...

Related municipalities

The park crosses the borders of 55

cities A city is a human settlement of notable size.Goodall, B. (1987) ''The Penguin Dictionary of Human Geography''. London: Penguin.Kuper, A. and Kuper, J., eds (1996) ''The Social Science Encyclopedia''. 2nd edition. London: Routledge. It can be def ...

, 14

towns A town is a human settlement. Towns are generally larger than villages and smaller than cities, though the criteria to distinguish between them vary considerably in different parts of the world. Origin and use The word "town" shares an ori ...

, and one

village A village is a clustered human settlement or community, larger than a hamlet but smaller than a town (although the word is often used to describe both hamlets and smaller towns), with a population typically ranging from a few hundred to ...

: *

Ehime is a prefecture of Japan located on the island of Shikoku. Ehime Prefecture has a population of 1,342,011 (1 June 2019) and has a geographic area of 5,676 km2 (2,191 sq mi). Ehime Prefecture borders Kagawa Prefecture to the northeast, Tokush ...

Ikata is a small peninsula town located in Nishiuwa District, Ehime Prefecture, Japan. , the town had an estimated population of 8,497 in 15638 households and a population density of 90 persons per km². The total area of the town is Following a rec ...

Imabari 270px, Imabari City Hall 270px, Aerial view of Imabari city center is a city in Ehime Prefecture, Japan. It is the second largest city in Ehime Prefecture. , the city had an estimated population of 152,111 in 75947 households and a population ...

, Kamijima,

Matsuyama file:Matsuyama city office Ehime prefecture Japan.jpg, 270px, Matsuyama City Hall file:Ehimekencho-20040417.JPG, 270px, Ehime Prefectural Capital Building is the capital Cities of Japan, city of Ehime Prefecture on the island of Shikoku in Japan ...

, Ōzu, Saijō, Yawatahama *

Fukuoka is the sixth-largest city in Japan, the second-largest port city after Yokohama, and the capital city of Fukuoka Prefecture, Japan. The city is built along the shores of Hakata Bay, and has been a center of international commerce since ancie ...

Kitakyushu is a Cities of Japan, city located in Fukuoka Prefecture, Japan. As of June 1, 2019, Kitakyushu has an estimated population of 940,978, making it the second-largest city in both Fukuoka Prefecture and the island of Kyushu after the city of Fuku ...

Hiroshima is the capital of Hiroshima Prefecture in Japan. , the city had an estimated population of 1,199,391. The gross domestic product (GDP) in Greater Hiroshima, Hiroshima Urban Employment Area, was US$61.3 billion as of 2010. Kazumi Matsui h ...

Etajima , also called , ''Nomijima'', ''Nomi Island'', or is an island in Hiroshima Bay located in southwestern Hiroshima Prefecture, Japan. The mess with island name originates from the ancient (and possibly legendary) strait at now town . Geography Th ...

, Fukuyama,

Hatsukaichi is a city located in Hiroshima Prefecture, Japan. The name derives from a market traditionally held on the 20th of each month with ''hatsuka'' (廿日) meaning "20th day" and ''ichi'' (市) translating to "market". The market continues to this day ...

Higashihiroshima is a city located in Hiroshima Prefecture, Japan. As of July 31. 2016 the city has an estimated population of 185,418 and a population density of 291.85 persons per km2. The total area is 635.32 km2. Higashihiroshima is a university town of ...

Kure is a port and major shipbuilding city situated on the Seto Inland Sea in Hiroshima Prefecture, Japan. With a strong industrial and naval heritage, Kure hosts the second-oldest naval dockyard in Japan and remains an important base for the Japan M ...

, Mihare,

Onomichi is a city located in Hiroshima Prefecture, Japan, facing the Inland Sea. The city was founded on April 1, 1898. As of April 30, 2016, the city has an estimated population of 141,811 and a population density of 497.8 persons per km2. The total a ...

, Ōsakikamijima, Ōtake,

Saka The Saka ( Old Persian: ; Kharoṣṭhī: ; Ancient Egyptian: , ; , old , mod. , ), Shaka (Sanskrit ( Brāhmī): , , ; Sanskrit (Devanāgarī): , ), or Sacae (Ancient Greek: ; Latin: ) were a group of nomadic Iranian peoples who hist ...

Takehara is a city located in Hiroshima Prefecture, Japan. The city was founded on November 3, 1958. As of 2016, the city has an estimated population of 26,035 and a population density of 220 persons per km2. The total area is 118.30 km2. Ōkun ...

* Hyōgo: Aioi,

Akashi Akashi may refer to: People *Akashi (surname) Places *Akashi, Hyōgo *Akashi Station, a Japanese railroad station on the Sanyō Main Line *Akashi Strait *Akashi Kaikyō Bridge, crossing the former *Akashi Castle *Akashi Domain * Akashi, the name ...

, Akō, Ashiya, Awaji,

Himeji 260px, Himeji City Hall is a city located in Hyōgo Prefecture in the Kansai region of Japan. , the city had an estimated population of 525,682 in 227,099 households and a population density of 980 persons per km². The total area of the city is ...

Kobe Kobe ( , ; officially , ) is the capital city of Hyōgo Prefecture Japan. With a population around 1.5 million, Kobe is Japan's seventh-largest city and the third-largest port city after Tokyo and Yokohama. It is located in Kansai region, whic ...

Minamiawaji is a city in the southern part of Awaji Island in Hyōgo Prefecture, Japan. , the city had an estimated population of 45,489 kn 19856 households, and a population density of 200 persons per km².The total area of the city is . Geography The cit ...

Nishinomiya 270px, Nishinomiya City Hall 270px, Aerial view of Nishinomiya city center 270px, Hirota Shrine is a city located in Hyōgo Prefecture, Japan. , the city had an estimated population of 484,368 in 218948 households and a population density of 48 ...

, Sumoto, Takarazuka, Tatsuno *

Kagawa may refer to: * , the smallest prefecture of Japan by area, located on the island of Shikoku * , a district in Kagawa Prefecture * , a town located in Kagawa District * , train station in Chigasaki, Kanagawa Prefecture * Kagawa (surname) Kagawa (w ...

: Higashikagawa, Kan'onji,

Kotohira is a town located in Nakatado District, Kagawa Prefecture, Japan. , the town had an estimated population of 8,105 in 3618 households and a population density of 960 persons per km². The total area of the town is . The town is best known as t ...

, Mannō,

Marugame is a city located in Kagawa Prefecture, Japan. , the city had an estimated population of 108,541 in 46101 households and a population density of 970 persons per km². The total area of the city is . Geography Marugame is located in north-ce ...

, Mitoyo,

, Sakaide, Sanuki,

Tadotsu 270px, Shorinji Kempo head dōjō is a town located in Nakatado District, Kagawa Prefecture, Japan. , the town had an estimated population of 22,124 in 10365 households and a population density of 270 persons per km². The total area of the ...

Takamatsu 270px, Takamatsu City Hall 270px, Aerial view of Takamatsu city center 270px, View from Yashima to Takashima port is a city located in Kagawa Prefecture, Japan. , the city had an estimated population of 414,134 in 190120 households and a popul ...

, Tonoshō, Zentsūji * Ōita: Bungotakada, Himeshima,

Kunisaki is a small coastal city located in Ōita Prefecture, Kyushu, Japan. It is located on the Kunisaki Peninsula facing the Seto Inland Sea. Mostly covered by forests and farmlands, the peninsula is dotted with temples. The modern city of Kunisaki w ...

, Ōita *

Okayama is the capital city of Okayama Prefecture in the Chūgoku region of Japan. The city was founded on June 1, 1889. , the city has an estimated population of 720,841 and a population density of 910 persons per km2. The total area is . The city is ...

: Asakuchi, Bizen,

Kasaoka is a city located in Okayama Prefecture, Japan. The city was founded on April 1, 1952. The municipal district also includes 31 outlying islands including seven inhabited islands in the Kasaoka Islands group. As of February 28, 2017, the city h ...

Kurashiki is a historic city located in western Okayama Prefecture, Japan, sitting on the Takahashi River, on the coast of the Inland Sea. As of March 31, 2017, the city has an estimated population of 483,576 and a population density of 1,400 persons per ...

, Setouchi,

Tamano is a city located in southern Okayama Prefecture, Japan. The city was officially founded on August 3, 1940. As of October 1, 2016, the city has an estimated population of 60,101 and a population density of 580 persons per km². The total area i ...

Tokushima is a prefecture of Japan located on the island of Shikoku. Tokushima Prefecture has a population of 728,633 (1 October 2019) and has a geographic area of 4,146 km2 (1,601 sq mi). Tokushima Prefecture borders Kagawa Prefecture to the north, E ...

Naruto ''Naruto'' is a Japanese manga series written and illustrated by Masashi Kishimoto. It tells the story of Naruto Uzumaki, a young ninja who seeks recognition from his peers and dreams of becoming the Hokage, the leader of his village. T ...

Wakayama Wakayama may refer to: *Wakayama Prefecture, a prefecture of Japan *Wakayama (city) Wakayama City Hall is the capital city of Wakayama Prefecture in the Kansai region of Japan. , the city had an estimated population of 351,391 in 157066 househol ...

* Yamaguchi:

Hikari may refer to: Places *Hikari Station, a station on Sanyō Main Line in Hikari, Yamaguchi * Hikari, Chiba, a former town in Sousa District, Chiba, Japan *Hikari, Yamaguchi, a city in Yamaguchi Prefecture, Japan People *Hikari (name), people and ...

Hirao is a town located in Kumage District, Yamaguchi Prefecture, Japan. As of 2016, the town has an estimated population of 12,643 and a density of . The total area is . Geography Neighbouring municipalities * Yanai * Kaminoseki * Tabuse ...

Hōfu is a city located in Yamaguchi Prefecture, Japan. As of September 30, 2016, the city has an estimated population of 117,387 and a population density of 622.44 people per km2. The total area is 188.59 km2. History Hōfu (防府) means "the c ...

Iwakuni is a city located in Yamaguchi Prefecture, Japan. History Iwakuni was formerly the castle town of the Iwakuni han, which was formed by Lord Hiroie Kikkawa after he was banished there for supporting the defeated shōgun. The Kikkawa clan ruled ...

Kaminoseki is a town located in Kumage District, Yamaguchi Prefecture, Japan. As of 2022, the town has an estimated population of 2,193 and a density of . The total area is . Geography Islands * Iwaishima * Yashima * Nagashima Neighbouring munic ...

Kudamatsu is a city in Yamaguchi Prefecture, Japan. , the city has an estimated population of 55,119, with 24,392 households and a population density of 616 persons per km2. The total area is 89.44 km2. The city was founded on November 3, 1939, being ...

Shimonoseki is a city located in Yamaguchi Prefecture, Japan. With a population of 265,684, it is the largest city in Yamaguchi Prefecture and the fifth-largest city in the Chūgoku region. It is located at the southwestern tip of Honshu facing the Tsushim ...

Shūnan is a city located in east central Yamaguchi Prefecture, Japan. As of October 1, 2016, the city has an estimated population of 143,959 and a population density of 220 persons per km2. The total area is 656.13 km2. The modern city of Shūna ...

Suō-Ōshima is a town and an island located in Ōshima District, Yamaguchi Prefecture, Japan. Suō-Ōshima was formed on October 1, 2004 from the merger of the former towns of Ōshima, Kuka, Tachibana and Tōwa, all from towns of Ōshima District. As ...

Tabuse is a town located in Kumage District, Yamaguchi Prefecture, Japan. In 2016, the town had an estimated population of 15,200 and a density of 300 persons per km². The total area is 50.35 km². In 2018, a civil servant reported property ta ...

, Yanai