Guide
The Usuki Castle Ruins, located in Usuki City, Oita Prefecture, are the remains of a historic fortress. Built around the Eiroku era (approx. 1562–1566) by Otomo Sorin, the site is also known as "Nyusima Castle" or "Kame-jo" (Turtle Castle) due to its unique shape. Today, the area has been developed into a public park where visitors can see surviving structures such as watchtowers, stone walls, and dry moats. The design is particularly notable for its strategic defensive layout, taking advantage of the natural topography of the island-like terrain.
While there are various theories regarding its construction, it is widely believed that Otomo Sorin established the castle. The name "Kame-jo" (Turtle Castle) comes from the way the land resembles a turtle. The fortification process was largely completed during the transition between the Otomo clan's rule and the arrival of the Inaba clan. Over time, the structure evolved to enhance military functions, such as the construction of the Sannomaru area near the current Gionsu. Although much of the castle was dismantled during the Meiji era (1868), the preserved remains serve as a vital link to the region's storied past.
The ruins (now known as Usuki Park) feature several significant historical structures. Notable landmarks include the Utotoguchi Gate Watchtower and the Tatami Watchtower. Visitors can also explore the dry moats, gate sites, well sites, and the massive stone walls that demonstrate the castle's defensive capabilities. The way the architecture integrates with the natural landscape provides a fascinating look at ancient Japanese fortification techniques.
The most spectacular time to visit is from March to April, when the arrival of spring brings a breathtaking display of cherry blossoms. The park is transformed into a sea of soft pink, attracting many visitors for hanami (flower viewing). For the best experience, visit during the bright daylight hours of the afternoon. If you wish to study the intricate details of the stone walls and architectural structures, a clear, sunny day is highly recommended.
Visitors can enjoy a historical walking tour to learn about medieval Japanese castle architecture. By exploring the stone walls, dry moats, and gate sites, you can truly feel the atmosphere of a former military stronghold. The park offers a peaceful way to experience the harmony between historical ruins and natural beauty. A stroll through the park during the cherry blossom season is a particularly delightful way to experience the changing seasons.
The castle ruins are now a well-maintained park and a beloved community space for locals. The surrounding area retains the atmosphere of an old castle town, allowing visitors to wander through the neighborhood and feel the historical depth of the region.
We recommend wearing comfortable walking shoes, as the park features uneven terrain, stone walls, and various steps. While there is no entrance fee to the park, please carry cash if you plan to use nearby facilities or shops. English signage is limited, so it may be helpful to look up historical terms in advance. No reservations are required for entry.