These sprawling grounds south of Sanmachi-suji house the only remaining prefectural office building of the Tokugawa shogunate, originally the administrative centre for the Kanamori clan. The present main building dates back to 1816 and was used as local-government offices until 1969. There's also a rice granary, a garden and a torture chamber with explanatory detail. Free guided tours in English are available (reservations advised).