Kyushu's smallest prefecture, Saga is located on the northwest corner of the island, bordered by the Genkai Sea and the Tsushima Strait to the north and the Ariake Sea to the south.
A number of towns and villages in Saga have merged with larger neighboring cities, as part of the ongoing nation-wide process of mergers and dissolution of municipalities.
On October 1, 2005, the towns of Morodomi, Yamato and Fuji (all from Saga District) and the village of Mitsuse from Kanzaki District merged into the city of Saga.