A medieval castle ruin in Nagaizumi-cho, known as a Sengoku-period remnant contested by the Imagawa, Takeda, and Hojo clans. Earthen ramparts and dry moats built on the hillside remain in good condition, evoking the defensive structures of the era. The castle site offers views of Mt. Fuji and Mt. Ashitaka and is popular as a scenic hiking course. Designated a prefectural historic site, it is an im…

Developed by the Imagawa in the 15th–16th century Sengoku period, it later became a strategic stronghold during Takeda Shingen's campaigns into Totomi and Suruga. After the fall of the Takeda it came under Tokugawa control and is said to have been abandoned in the early Edo period. Currently managed…