Historic Ruins
○ Second 100 Castles

Tsushima Kanazashi Castle

The main castle of the So clan who ruled Tsushima and managed Japan's official relations with Korea throughout the Edo period. The stone walls and Yanagidomon gate in Izuhara town are well-preserved, and the nearby Banshoin clan mausoleum is a designated important cultural property.

Japanese Name対馬・金石城
PrefectureNagasaki Prefecture (長崎県)
RegionKyushu (九州)
Castle TypeHill Castle
Year Built17th c.
Designation続100名城
Coordinates34.2167, 129.2667

Tsushima Kanazashi Castle served as the political and administrative heart of the Tsushima domain throughout the Edo period, making it a crucial point of contact between Japan and Korea. As the seat of the powerful Sō clan, this fortress played an instrumental role in managing Japan's carefully regulated trade and diplomatic relations with the Korean peninsula for over two centuries. The castle's strategic location on the island positioned it perfectly for this vital international function.

Constructed in the 17th century, the castle developed gradually as the Sō clan consolidated their power and expanded their responsibilities. The clan's growing importance led to successive modifications and fortifications that reflected both defensive needs and the clan's increasing wealth and status. This development pattern was typical of major domain capitals during the Edo period.

The castle's architectural features reveal its dual purpose as both a military fortress and administrative center. The stone walls and the distinctive Yanagidomon gate located in present-day Izuhara town remain well-preserved, offering visitors tangible evidence of the structure's original design. The nearby Banshoin clan mausoleum, designated as an important cultural property, adds another layer of historical significance to the site and provides insight into the religious and cultural practices of the ruling family.

Visitors exploring the ruins today can examine the remaining stonework and foundations that trace the castle's original layout. The site is included in the Continued Selection of One Hundred Castles, recognizing its historical importance to Japanese castle heritage. The combination of architectural remnants and nearby cultural sites makes it a worthwhile destination for those interested in Japan's diplomatic history and Edo-period castle architecture.

Tsushima Kanazashi Castle is recognized as one of Japan's second 100 castles as designated by the Japan Castle Foundation, a distinction that highlights its historical and architectural importance among the hundreds of castle sites across the country. Its design reflects the defensive priorities and construction techniques of the feudal period, with origins dating to 17th c.. Visitors traveling to Nagasaki Prefecture can explore the site alongside other regional historical attractions, and the location is well served by public transportation from major nearby cities.