Usuki Castle is classified as a hilltop castle, and is located in Ōita Prefecture. During the pre-modern age, it found itself within the borders of Bungo Province. It is associated with the Ōtomo, Inaba clans. Dates in use: 1562 - 1873.

Ōtomo Sōrin built this castle on what was a small oval-shaped island that touched the coastline at just one point. The site was chosen as it offered good position to better defend against his enemies. The island has long since been swallowed up by land reclamation followed by the city of Usuki itself. The two surviving Edo period turrets are complimented by the rebuilt Daimon Turret.

Some mystery still surrounds the structure & appearance of the main tower. However, based on research, it is believed to have been a three-layer, four-story tower, 12 meters in height. It was connected to the Tsuke Turret by a series of two-story, hall-like turrets.

There is plenty to see in the castle town too. Several streets present beautifully preserved shops, houses & temples. And beyond these few streets are countless more crumbling storehouses awaiting restoration.

Timeline

1562	The castle was built by Ōtomo Sōrin. He moved his headquarters from Funai castle in the north.
1578	Sōrin converted to the Christian faith & became known as Don Francisco.
1587	Sōrin died in a town located south-east call Tsukumi.
1600	Following the battle of Sekigahara, the Inaba clan were awarded the Usuki domain. In November, 20 hereditary retainers of the Inaba clan enter the castle. Then on December 25th, Inaba Sadamichi & his son entered the castle.
1644	The Tatami Turret was built sometime between 1644 & 1648.
1655	Repairs were made to the Main tower & its foundations.
1763	The Tatami Turret burnt down & was built in the following years.
1854	The Utonoguchimon wagi Turret was rebuilt. It had been known previously as the onteppo Gusuri Turret.
1873	The main tower & 31 turrets were torn down leaving just two buildings.
1877	With most defensive structures gone, it was no surprise that the castle fell within one day during the Seinan Rebellion.
2001	The Daimon Gate was rebuilt.

Historical recognition

Site	Prefectural Historic Site