Nagasaki PrefectureNagasaki Prefecture (長崎県, Nagasaki-ken) is a prefecture of Japan, mainly located on the island of Kyūshū, although it also includes a number of islands off Kyūshū's northwest coast - including Tsushima and Iki. Nagasaki Prefecture has a population of 1,246,481 (1 February 2025) and has a geographic area of 4,130 km (1,594 sq mi). Nagasaki Prefecture borders Saga Prefecture to the northeast.
Fukuoka PrefectureFukuoka Prefecture (福岡県, Fukuoka-ken; Japanese pronunciation:) is a prefecture of Japan located on the island of Kyūshū. Fukuoka Prefecture has a population of 5,081,879 (1 October 2025) and has a geographic area of 4,986 square kilometres (1,925 sq mi). Fukuoka Prefecture borders Saga Prefecture to the southwest, Kumamoto Prefecture to the south, and Ōita Prefecture to the southeast.
Ariake SeaThe Ariake Sea (有明海, Ariake-kai) is a body of salt water surrounded by Fukuoka, Saga, Nagasaki, and Kumamoto Prefectures, all of which lie on the island of Kyūshū in Japan. It is the largest bay in Kyūshū. Its deepest point is only about 20 meters deep, and extreme tides exceed 4 meters (13 ft), covering roughly 1,700 square kilometres (660 sq mi). Isahaya Bay is a branch of the Ariake Sea. Across the Amakusa Islands lies the Yatsushiro Sea.
Prefectures of JapanJapan is divided into 47 prefectures (都道府県, todōfuken, [todoːɸɯ̥ꜜkeɴ] ), which rank immediately below the national government and form the country's first level of jurisdiction and administrative division. They include 43 prefectures proper (県, ken), two urban prefectures (府, fu: Osaka and Kyoto), one regional prefecture (道, dō: Hokkaidō) and one metropolis (都, to: Tokyo).
Karatsu, SagaKaratsu (唐津市, Karatsu-shi) is a city located in Saga Prefecture on the island of Kyushu, Japan. Its name, formed from the Japanese word roots 唐 kara (China, or continental East Asia in general), and 津 tsu (port), signifies its historical importance as an ancient trading port between Japan with China and Korea. As of 1 September 2026, the city had an estimated population of 111,413 in 51,678 households, and a population density of 228.5 persons per km2.
Imari, SagaImari (伊万里市, Imari-shi) is a city located in Saga Prefecture on the island of Kyushu, Japan. As of 1 June 2024, the city had an estimated population of 51,875 in 23,874 households, and a population density of 200 persons per km2. The total area of the city is 255.26 km2 (98.56 sq mi). Imari is most notable because of Imari porcelain, which is the European collectors' name for Japanese porcelain wares made in the town of Arita, Saga Prefecture.
KyushuKyushu (, Kyūshū; pronounced, lit. 'nine provinces') is the third-largest and most southerly of Japan's four main islands. In the past, it has been known as Kyūkoku (九国, "Nine Countries"), Chinzei (鎮西, "West of the Pacified Area") and Tsukushi-no-shima (筑紫島, "Island of Tsukushi"). The historical regional name Saikaidō (西海道; lit. West Sea Circuit) referred to Kyushu and its surrounding islands.
JapanJapan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asian mainland, it is bordered to the west by the Sea of Japan, the Sea of Okhotsk in the north, and the East China Sea in the south. The Japanese archipelago consists of four major islands alongside over 14,000 smaller islands.
Sea of JapanJapanese nameKanji日本海HiraganaにほんかいNorth Korean nameChosŏn'gŭl조선동해Hancha朝鮮東海Literal meaningEast Sea of KoreaSouth Korean nameHangul동해Hanja東海Literal meaningEast SeaRussian nameRussianRomanizationYaponskoye moreManchu nameManchudergi mederiThe Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East.
Saga (city)Saga (佐賀市, Saga-shi; Japanese pronunciation: [saꜜ.ɡa, -ŋa, sa.ɡaꜜ.ɕi, -ŋaꜜ.ɕi]) is the capital city of Saga Prefecture, located on the island of Kyushu, Japan. As of 30 April 2024, the city had an estimated population of 227,138 in 104,354 households, and a population density of 530 persons per km2. The total area of the city is 431.81 km2 (166.72 sq mi).
Tosu, SagaTosu (鳥栖市, Tosu-shi) is a city located in the eastern part of Saga Prefecture on the island of Kyushu, Japan. As of 30 April 2024, the city had an estimated population of 74,334 in 33597 households, and a population density of 1000 persons per km2. The total area of the city is 71.72 km2 (27.69 sq mi).
IsthmusAn isthmus ( ; pl.: isthmuses or isthmi ; from Ancient Greekisthmós'neck') is a narrow piece of land connecting two larger areas across an expanse of water by which they are otherwise separated. A tombolo is an isthmus that consists of a spit or bar, and a strait is the sea counterpart of an isthmus, a narrow stretch of sea between two landmasses that connects two larger bodies of water.*As an Amazon Associate I earn from qualifying purchases.