Strategically located along a river which shares its name, Nakatsu Castle is one of only three water castles in Japan. The its adjoining castle town was also designed to hinder the approach of attackers. Kuroda Yoshitaka (1546–1604) built Nakatsu Castle in 1588 after he was designated daimyo of the region by the warlord Toyotomi Hideyoshi (1537–1598). When Kuroda was moved to Fukuoka by the Tokugawa warlords in 1600, Hosokawa Tadaoki (1563–1646) replaced him and sent his son to occupy the castle. Later, the domain would be ruled by the Ogasawara clan (from 1632) and the Okudaira clan (from 1717).
The neighborhoods surrounding the castle are home to numerous temples and shrines, many of which were built by the daimyo during the Edo period (1603–1867). The most famous of these temples is Goganji, which is known for its unusual crimson walls. The colored walls memorialize the slaughter of Utsunomiya Shigefusa (1536–1588) and his associates. In 1587 Kuroda Yoshitaka had taken over the surrounding area from Shigefusa and in 1588 Shigefusa conspired to kill Kuroda Yoshitaka and take back power. When his plan was found out, he was killed here at Goganji along with his men. Supposedly, the bloodstains on the walls could not be covered with any amount of whitewash, and the walls were ultimately painted red instead. The visible notches on the exterior and interior of the building are believed to be from the fighting. Other notable temples in the area include Enryuji Temple, Jishoji Temple, and Ennoji Temple.
