main body
photo of Saikai National Park

Characteristics

Crossroad Connecting the Islands, Ocean, Nature, and Culture.
Date of Designation: March 16, 1955
Area: 24,646 ha (land area)
Related Prefecture: Nagasaki
Situated in northwestern Kyushu, Saikai National Park is noted for its magnificent archipelago seascapes from the more than 400 islands, large and small, including the Kujuku Shima Islands of Sasebo, Ikitsuki-jima and Hirado-jima Islands, and the Goto Islands. The park is famous for the myriad vistas that can be found across the micro islands and a distinct geographical feature of dendritic drowned valleys on the Kujuku Shima Islands, steep sea cliffs on the Ikitsuki-jima and Hirado-jima Islands with well-developed columnar joints, wave-eroded cliffs of Cape Osezaki on the Goto Islands, and the open-sea archipelago seascape. The park also commands a view of different volcanic landforms from the Hirado-jima Island to the Fukue-jima Island.
In response to these complex geographical features, the park boasts a wide-ranging biodiversity. The shallow water is populated with macrophytes beds and the inner part of the bay cultivates tidal flats, making it the best breeding ground for rare species. The land area is lush with a evergreen broad leaved secondary forest and noted for the controlled field burning and rocky ridges, while the diverse flora from continental elements to Southeast Asia elements and endemic species by isolation effect. In addition, the large-scale migration of the Pernis ptilorhyncus traveling westward and the Accipiter soloensis traveling southward in autumn is simply impressive.
As the park is also a place for humans, the culture and churches related to the religious beliefs of Christianity, whaling culture, and the military ruins related to the Sasebo Naval District are also some of the must-see sights.

Terrain/ Scenery

photo of Ajikajima Island formed with well-developed columnar joints

Ajikajima Island formed with well-developed columnar joints.

Landform of the Hirado-jima and Kujuku Shima Islands Area
The Ikitsuki-jima Island, in the Hirado area, has a well-developed sea cliff especially in the west area and has extensive basalt columnar joints. Hirado-jima Island consists of a variety of volcanic rocks and is noted for its conglomerate stones, the typical eroded volcanic landform seen on Mt. Sashidake and Mt. Shijiki, Kawachi Pass, and the lava plateau of Mt. Yasuman , as well as the columnar joints formed on Ajika Jima Island in the southwest, all of which are worthy of special mention.
photo of Ojikase on the Minami-Kujuku Shima Islands, where erosion benches are developed.

Ojikase on the Minami-Kujuku-Shima Islands, where erosion benches are developed.

The Kujuku Shima Islands area has the distinct geographical feature of dendritic drowned valleys and the seascape of 208 densely scattered islands and inlets from Emukae Bay to Tawaragaura to exhibit a unique scenery only available here. The inland area on the main island is a low relief hill while the major mountains of Mt. Eboshi and Mt. Shokan have a lava plateau comprising basalt rocks.
photo of Tamanoura Bay, viewed from the of Mt. Nanatsudake

Tamanoura Bay, viewed from the of Mt. Nanatsudake

Topography and Geology of the Goto Islands Area
Goto Islands is a chain of seven main islands and numerous inlets of various sizes in the East China Sea, measuring approximately 90 km in length.
The geographical features were formed by movement and folding along a fault during the middle of the Tertiary period with sedimentation, settling, and volcanic activity. Wakamatsu Seto Strait and Tamanoura Bay are marked by well-developed complex coastlines and dendritic drowned valleys, as well as the volcanic landforms of a pyroclastic cone and shield volcaanos in the trenches.
photo of Saga-no-Shima Island's sea cliffs are sites to behold the inner structure of a volcano.

Saga-no-Shima Island's sea cliffs are sites to behold the inner structure of a volcano.

In the coastal strip facing the open sea, while the Sagano Shima Island is characterized by its significant development of sea cliffs and marine erosion, exhibiting a harsh look of the archipelago seascapes unique to the open sea, the calm seascapes dotted with numerous islands and inlets with sand spits and land-tied islands lie over the inland area.
photo of The Wakamiya-ura tidal flaton the Hirado Jima Island

The Wakamiya-ura tidal flaton the Hirado-jima Island

Tidal Flats
There are tidal flats along the complex coastline in various parts, which are abundantly populated with rare marine life such as Japanese horseshoe crabs.

Plants

The park boasts a diverse environment where the ocean and land meet, as well as its extremely rich flora, thanks to the ancient connections to the continent during the ice age and the subsequent influence of the inflow of the Tsushima Warm Current.
A chain of small and large islands and inlets lying north and south helps support the creation of wide-ranging biodiversity. While the ocean is populated with seagrass beds and tidal flats nurturing a rich biota, the land is characterized by a unique environment the burning of grasslands, and jutting rocks, although it is mostly secondary evergreen broadleaf forest.
For the maintenance of meadows and grassland landscape, fields are burned in February on Kawachi Pass on Hirado-jima Island, Mt. Sashidake, Jodan-no-no, and Mt. Onidake on Fukue-jima Island.
photo of Controlled field burning in the Mt. Onidake

Controlled field burning in the Mt. Onidake

photo of Seagrass bed on the Mina Shima Island

Seagrass bed on the Mina Shima Island

The macrophytes inhabited by seed plants eel grass and Helobiales hydrocharitaceae, and the algae Sargassum fulvellum and Ecklonia cava support the bountiful marine biota.

The forests comprise mostly secondary forest of Castanopsis, Quercus, and Camellia japonica, which have been used as a fuelwood forest, enveloped in fresh green.
photo of An evergreen broadleaf forest in Mt. Shokan

An evergreen broadleaf forest in Mt. Shokan

Wildlife

There are tidal flats along the complex coastline in various parts, which are abundantly populated with rare marine life such as Japanese horseshoe crabs. Corresponding to its complex marine environment, the park is inhabited by multifarious fauna and serves as a migratory pathway for numerous migrant birds as it is marked by the farthest land point on the migration path. The periphery of the marine park zone on the Goto Islands is home to well-developed colonies of corals such as the Acropora spp.
photo of The Wakamiya-ura tidal flat on the Hirado Jima Island

The Wakamiya-ura tidal flat on the Hirado Jima Island

photo of Acropora spp

Acropora spp.

Culture

The park is filled with attractions from historical resources of the Christian faith and coastal whaling culture indicating the coexistence with whales to the fortress ruins that protect the Sasebo Naval District.
photo of Kakure Kirisitan Seichi

Kakure Kirisitan Seichi
(Holy Ground of Crypto-Christians: Mt. Yasuman)

Christians (Mt. Yasuman) The Catholic faith lay hidden due to Anti-Christian Edicts and became a syncretism of Shintoism and Buddhism over time. (The photo is a stone shrine on Mt. Yasuman, which attracted many people of faith as a sacred place for enshrining the Christian God.)
photo of Kyu Gorin Kyokaido (Former Gorin Church´╝ë

Former Gorin Church

Nestled on the Goto Islands, this wooden church is known to be the oldest church in existence and was built by the Christian community who were re-converted to Catholicism. It is a constituent asset of the proposed World Heritage sites.
photo of Former Nokubi Church

Former Nokubi Church

It is a church used by the Catholic community living on Nozaki Shima Island, which is now a deserted island, and is a constituent of UNESCO's Tentative List of World Heritage sites.
photo of Kindai Hogei (Modern Whaling)

Kindai Hogei (Modern Whaling)

Before the arrival of Western European whaling fleets to catch most of the whales in the adjoining seas, this area was the center of whale fishing.
photo of Marudeyama Kansokujo

Marudeyama Kansokujo (Marudeyama Observatory)

One of the eyes of the batteries on a fortress in Sasebo, which was initially built to protect the Sasebo Naval Station from the Russian fleet.