Funai Castle

Funai Castle (also known as Ōita Castle, Hoyō Castle, or Hakuchi Castle) is a historic hirayama-style castle located in the center of Ōita City. Its construction began in the late Azuchi–Momoyama period under Fukuhara Naotaka and was later completed by Takenaka Shigetoshi after the Battle of Sekigahara. Funai Castle is also an example of a “sea castle,” as many daimyō who entered Kyushu at the time chose coastal locations for their residences—advantageous both for defense and for controlling maritime transport.

During the Edo period, Funai Castle served as the political headquarters of the Funai Domain. However, following the Meiji Restoration, most of the castle structures were dismantled, leaving behind only partial remains. Further devastation occurred during World War II, when the Ōita air raids destroyed several yagura towers and the Ōtemon Gate. Today, the castle grounds have been preserved as Ōita Castle Ruins Park, where stone walls, earthen walls, and moats remain. Some original towers, such as the Hitojichi Yagura and the Sōmon Yagura, still stand and have been designated as historical sites of Ōita Prefecture.

In recent years, Ōita City has promoted the restoration and reuse of Funai Castle. Several yagura towers, the Ōtemon Gate, and the covered corridor bridge have been reconstructed in wood. On the former grounds of the Sannomaru, the Ōita Prefectural Government Office and the Ōita City Hall were built, making the castle site a place where history and modern administration coexist. The city has also been considering a potential reconstruction of the main tenshu keep. Although not yet realized, a temporary steel framework and lighting installation simulate the tenshu’s silhouette, with night illuminations attracting many locals and visitors.

Today, Ōita Castle Ruins Park serves not only as a relaxing space for citizens but also as an important cultural symbol of the city. The stone walls and moats still convey the castle’s former grandeur, while the reconstructed structures allow visitors to imagine the majestic sight it once was.