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.