Karatsu, Saga
Due to its proximity to mainland Asia, Karatsu has long been known as a stopover to Korea and China.Under ritsuryō, the current city area was part of the Hizen Province. In 1591, on the coast of the northern part of the city (formerly the town of Chinzei), Nagoya Castle was constructed. The following year, it became the location from which the Imjin War was launched by Toyotomi Hideyoshi. In the middle of 1593, Terasawa Hirotaka created the Karatsu domain and began governing it. In 1602, replacing Nagoya Castle, Karatsu Castle was constructed in what is now the heart of Karatsu. The tower of Karatsu Castle was built in 1966 .
Nishikawa Castle
Following the Siege of Odawara Castle in 1590, in which Tokugawa Ieyasu and Toyotomi Hideyoshi defeated the rival Hōjō clan of the east, Hideyoshi offered the newly acquired Kantō region to Ieyasu in exchange for his five domains, which included Mikawa. Ieyasu accepted the offer, and the Saigo clan accompanied him in his transfer to the east. The lord of Nishikawa Castle, Saigo Iekazu (son of Kiyokazu), was ordered to relocate to Oyumi Castle, in Shimōsa Province (incidentally, the Makino clan was ordered to a province to the northwest in the same year ). Custody of Nishikawa Castle and its surrounding lands was passed from the Saigo to the Ogasawara clan, but with the re-distribution of clans, Mikawa province was surrounded by vassals of Toyotomi Hideyoshi, and so Nishikawa Castle ceased to be a priority military structure. In 1661, Ogasawara Naga'aki, who was responsible for administering the region, was promoted to lordship over Yoshida Castle, and Nishikawa Castle was thereafter abandoned. As with many abandoned castles, local peasantry probably plundered the site for building materials such as stones and lumber.