Site of Kaneishi Castle and Garden
Kaneishi Castle was the main residence of the So family, the daimyo lords of Tsushima, from its establishment in 1528 until the late seventeenth century. The compound was initially relatively lightly fortified, but was turned into a castle with walls and watchtowers in the 1660s. The enlargement coincided with the rebuilding of the castle town of Izuhara after a destructive fire and was financed by profits earned from the flourishing trade between Tsushima and Joseon Korea.
Despite its expansion, Kaneishi Castle proved insufficient for the So family, and they moved their residence to the larger and grander Sajikihara Castle north of the town in 1678. The relocation may have been caused by the family’s diplomatic duties, foremost among which was the welcoming of regular embassies from Korea. These delegations, which were dispatched to the shogunate in Edo (modern Tokyo) via Tsushima, could consist of more than 450 participants. The So were tasked with accommodating the delegates on Tsushima and accompanying them on the journey to Edo.
The So family retained Kaneishi Castle as a secondary residence, and in the 1690s added a small garden centered on a pond in the shape of the Chinese character kokoro (心), which means “mind” or “heart.” The castle was last used for official purposes in 1811, when it served as a guest house for the shogun’s representatives during the final Joseon mission to Japan. That embassy did not travel any further than Tsushima as a cost-saving measure agreed between the two parties.
Some of the original walls of Kaneishi Castle remain on the site, which is now occupied by the Tsushima Museum, and the main gate and watchtower have been reconstructed. The garden had been built over, but it was restored in the 1990s and is open to the public.
