National Parks · Kagawa, Okayama, Hiroshima, Hyogo, Ehime, Yamaguchi, Tokushima, Wakayama, Fukuoka Prefecture, Oita

Setonaikai National Park

瀬戸内海国立公園せとないかいこくりつこうえんSetonaikai Kokuritsu Kōen

An inland sea of islands, straits and harbour towns

Setonaikai National Park protects the scenery of the Seto Inland Sea, the enclosed sea between Honshu, Shikoku and Kyushu with its hundreds of islands. Designated on 16 March 1934 as one of Japan's first three national parks, it spans ten prefectures and, counting its waters, is the largest national park in Japan.

Area: 672.8 km²National park · 1934UNESCO World Heritage · 1996Ramsar wetland · 2012

World Heritage: Itsukushima Shinto Shrine

Overview

Setonaikai National Park is not a single tract of land but a mosaic of islands, headlands, mountains and straits scattered across the Seto Inland Sea, from Awaji Island and the Rokkō range above Kobe in the east to the approaches of the Kanmon Strait and the coast of Ōita in the west. Its theme is a seascape: calm water dotted with green islands, fishing villages and terraced slopes, seen from viewpoints above the sea.

When Japan created its first national parks on 16 March 1934, Setonaikai was one of the three designated that day, together with Unzen and Kirishima. At first it covered only the Bisan Seto, the narrow waters between Okayama and Kagawa around Shōdoshima, Yashima and Washūzan; it was greatly enlarged in the 1950s to take in much of the Inland Sea. Counting its waters, it is the largest national park in the country, and its land spans ten prefectures.

The Inland Sea has been Japan's great highway since antiquity, and the park is correspondingly full of history: the floating shrine of Itsukushima, the tide-waiting port of Tomonoura, the battlefield of Yashima and the art islands of Naoshima and its neighbours.

Landscape and formation

The Seto Inland Sea occupies a zone of subsidence between the uplifted mountains of Chūgoku and Shikoku. When sea level rose after the last ice age, some 10,000 years ago, the sea flooded a lowland of basins and hills, leaving the tops as islands; the Japan Coast Guard counts more than 700 islands with a coastline of over 100 m.

Much of the landscape is built of weathered granite, which gives the characteristic white sand beaches and rounded hills crowned with pines, the ideal of hakusha seishō, 'white sand and green pines'. Between the basins, narrow straits such as Naruto, Akashi and Kurushima force powerful tidal currents, creating whirlpools and rich fishing grounds. Mesas of volcanic andesite such as Yashima and the gorges of Kankakei on Shōdoshima add a different, volcanic element.

Highlights

Itsukushima (Miyajima)
厳島Itsukushima
Sacred island with the shrine and its great torii standing in the sea, and the primeval forest of Mount Misen (535 m).
Shōdoshima
小豆島Shōdoshima
The second-largest island of the Inland Sea, with the volcanic gorge of Kankakei and olive groves.
Naruto whirlpools
鳴門の渦潮Naruto no Uzushio
Tidal whirlpools in the strait between Awaji and Shikoku, largest at spring tides.
Awaji Island
淡路島Awajishima
The largest island of the Inland Sea, whose coasts and hills form part of the park.
Washūzan
鷲羽山Washūzan
A granite hill at the tip of the Kojima Peninsula, the classic viewpoint over the islands of the Bisan Seto and the Seto Ōhashi bridges.
Yashima
屋島Yashima
A flat-topped andesite mesa above Takamatsu, site of a battle of the Genpei War and temple 84 of the Shikoku pilgrimage.
Tomonoura
鞆の浦Tomonoura
A harbour town where ships waited for the turning of the tides, preserving a stone lantern, landing steps and merchant houses.

Nature

IslandsItsukushima (Miyajima)ItsukushimaThe island where the shrine stands in the sea IslandsShodoshimaShōdoshimaOlives, soy sauce and a mountain gorge in the Inland Sea

Ecology

The Setouchi climate is dry and sunny, with mild winters, and the natural vegetation of evergreen broadleaf forest has largely given way to red-pine woods on thin granite soils. Primeval forest survives on Mount Misen, protected by the sanctity of Miyajima. The sea itself is shallow and productive, with eelgrass beds, tidal flats and fast straits that support sea bream, octopus and many other fish, as well as rare animals of the enclosed coast.

Flora

Japanese red pine
アカマツakamatsu
The tree of the granite hills, forming the 'green pine' of the Inland Sea's classic scenery.
Misen primeval forest
弥山原始林Misen genshirin
Evergreen forest of fir and broadleaf trees on Miyajima, a natural monument left largely untouched for religious reasons.
Eelgrass
アマモamamo
Seagrass meadows in shallow bays that serve as nurseries for fish.
Olive
オリーブorību
Introduced to Shōdoshima in the early 20th century and now part of the island's landscape.

Fauna

Finless porpoise
スナメリsunameri
The Inland Sea's small porpoise; its waters off Takehara were protected as a natural monument as early as 1930.
Horseshoe crab
カブトガニkabutogani
A 'living fossil' spawning on the tidal flats of the Inland Sea, notably around Kasaoka.
Red sea bream
真鯛madai
Grows firm in the fast currents of the straits and is the Inland Sea's most prized fish.
Miyajima dragonfly
ミヤジマトンボMiyajima tonbo
A rare dragonfly of Miyajima's brackish marshes, the reason the island was listed as a Ramsar site in 2012.

Culture

The Inland Sea linked the capital regions of Nara and Kyoto with Kyushu and the continent, and its ports, shrines and pirate strongholds are woven into Japanese history. The Taira clan made Itsukushima their shrine, the Genpei War was fought at Yashima, and the Murakami 'sea lords' controlled the straits of the Geiyo Islands in the medieval period. Tomonoura and other harbours flourished as tide-waiting ports on the route of Korean embassies and domain lords.

Since the 1990s several islands, above all Naoshima, Teshima and Inujima, have become known for contemporary art, and the Setouchi Triennale has been held every three years since 2010.

Itsukushima Shrine
厳島神社Itsukushima Jinja
A shrine built over the tidal flats, given its present form under Taira no Kiyomori in the 12th century.
Naoshima
直島Naoshima
An island of museums and outdoor art works by architects such as Andō Tadao.
Yashima-ji
屋島寺Yashima-ji
Temple 84 of the Shikoku 88-temple pilgrimage on the summit of Yashima.
Kankakei
寒霞渓Kankakei
A gorge of volcanic pinnacles on Shōdoshima, famous for autumn leaves.
Onomichi and the Shimanami islands
しまなみShimanami
The island chain crossed by bridges between Onomichi and Imabari, heartland of the Murakami sea lords.

History

1168
Taira no Kiyomori rebuilds Itsukushima Shrine in its present form.
1185
The Battle of Yashima is fought between the Taira and Minamoto.
1934
Setonaikai is designated on 16 March, one of Japan's first three national parks, initially around the Bisan Seto.
1950s
The park is greatly enlarged to cover much of the Inland Sea, including Awaji, Naruto and Rokkō.
1988
The Seto Ōhashi bridges link Okayama and Kagawa across the Bisan Seto.
1996
Itsukushima Shinto Shrine is inscribed on the World Heritage List.
1999
The Shimanami Kaidō completes a road link across the Geiyo Islands.
2012
Miyajima is listed as a Ramsar wetland.

Through the seasons

Spring

Hazy, calm seas and cherry blossom on the island hills; one of the best seasons for cycling the Shimanami Kaidō.

Summer

Hot and sunny, with swimming beaches on the islands; Miyajima's Kangensai boat festival takes place on a summer evening fixed by the lunar calendar.

Autumn

Clear views across the islands and maple colour at Kankakei and Momijidani on Miyajima.

Winter

Dry, mild and often sunny; the oyster season in Hiroshima Bay.

Routes and trails

Shimanami Kaidō
A cycling and road route of about 70 km across six islands and their bridges between Onomichi and Imabari.
Mount Misen on Miyajima
Several trails climb from the shrine through primeval forest to the summit; a ropeway covers most of the ascent.
Inland Sea island ferries
Ferries from Takamatsu, Uno and other ports connect Shōdoshima, Naoshima, Teshima and many smaller islands.
Naruto whirlpool boats
Sightseeing boats approach the whirlpools under the Ōnaruto Bridge; the whirlpools are strongest around spring tides.

Practical notes

The Sanyō Shinkansen runs along the northern shore; Okayama, Fukuyama, Hiroshima and Shin-Kobe are the main gateways.
The park is scattered: plan by area (Miyajima, Bisan Seto islands, Shimanami, Awaji–Naruto) rather than as one trip.
Whirlpool viewing depends on the tides; the tide tables published locally show the best times.
Miyajima's deer are wild animals; feeding them is discouraged.

Frequently asked questions

Which were Japan's first national parks?

Setonaikai, Unzen and Kirishima were designated together on 16 March 1934, the first three national parks of Japan.

Is Miyajima part of a national park?

Yes. Miyajima (Itsukushima) lies within Setonaikai National Park, and the shrine is a World Heritage Site.

How many prefectures does the park cover?

Ten: Hyogo, Wakayama, Okayama, Hiroshima, Yamaguchi, Tokushima, Kagawa, Ehime, Fukuoka and Ōita.

How many islands are there in the Seto Inland Sea?

The Japan Coast Guard counts more than 700 islands with a coastline of over 100 m; including rocks, there are several thousand.

Why are the whirlpools at Naruto so strong?

The tide in the Pacific and in the Inland Sea is out of phase, so water rushes through the narrow Naruto Strait at high speed and forms whirlpools where fast and slow currents meet.

Sources

1.環境省_瀬戸内海国立公園 (opens in a new tab) — 環境省 (Ministry of the Environment)
2.環境省_国立公園_国立公園一覧 (opens in a new tab) — 環境省 (Ministry of the Environment)
3.Itsukushima Shinto Shrine (opens in a new tab) — UNESCO World Heritage Centre
4.National Parks of Japan (opens in a new tab) — Ministry of the Environment, Government of Japan