Land area: 24,646 ha
Designated on 16 Mar, 1955
On a sea of shining blue water, is a cluster of many islands. The rich vegetation on the islands makes the blue of the seawater look deeper and it indicates the richness of the natural environment here. As this area is close to the Chinese Continent, it used to be a base for overseas trade. Here, historic sites and other cultural assets have been conserved in the rich natural setting, and they make the park an interesting place in terms of both nature and culture.
Saikai National Park is located in the northwestern part of Kyushu and it consists of the ocean and many islands. It is mainly composed of three areas: the Kujukushima Islands, the coastal area which includes Hiradoshima and Ikitsukijima Islands, and the Gotoretto Islands. Combining the Kujukushima Islands and main part of the Gotoretto Islands, the park contains more than 400 islands, large and small.
Kujukushima Islands off the coast of Sasebo is composed of 208 islands. Among all the groups of islands in Japan, here, the distance between each island is closest, i.e. the density of islands is highest, and this density contributes to creating beautiful landscapes. The contrast of the islands, covered with evergreen broad-leaved forests in deep green, with the blue ocean is vivid and beautiful. The view can be seen from observatory decks situated on highlands in the inland area of the main part of Kyushu, such as Mt. Eboshidake and Mt. Yumiharidake. Pleasure boat excursions on the sea are also very popular.
Hiradoshima Island is located in the north of the Kujukushima Islands. Mt. Shijikiyama (347 m) on the south edge of the island has served as a landmark for passing ships because it has a unique figure with a pointed top and can be recognized easily from a distance.
The Gotoretto Islands are the only pelagic archipelago in Japan and are composed of about 250 islands in different sizes. Fukuejima Island, the largest island in Gotoretto, has a scenic spot on its western tip. At Cape Osezaki, a line of sheer cliffs about 160 m high soars along the ocean coast for as long as 20 km. Mt. Ontake on the island is in a peculiar volcanic landform consisting of a homate on top of an aspite. The mountain is covered with lawn grasses and commands a great view.
The cliff on Saganoshima Island in the northwestern part of the sea area is notable as a section of the crater is exposed as the result of wave erosion.
The vegetation in the park area is dominated by Japanese black pine (Pinus thunbergii) woods and evergreen broad-leaved forests of Japanese chinquapins and evergreen oaks. In some places, subtropical plants such as palms and ferns can be seen. Camellia woods in Hisakajima Island and sasanqua woods in Hiradoshima Island are noteworthy.
Off the coast of Fukuejima and Wakamatsujima Islands, reef-building coral and colorful soft coral grow and tropical fish swim. The area is designated as a Marine Park Zone.
The park area is also an important historic site. In Hiradoshima Island and its environs, trade with the Chinese Continent and Europe has been practiced since early times and as the area has a long history of exchange with foreign countries, there are many churches and historical places. It is a unique feature of the park that there are many spots of cultural interest.