Sagiyama Castle

Sagiyama Castle, located in the modern city of Gifu within Gifu Prefecture, Japan, was originally constructed around 1185 by Satake Hideyoshi. Built during the late Heian period, this mountaintop structure stood atop Mount Sagi, a modest peak rising only 68 meters. Unlike many contemporary fortifications designed primarily for defense, Sagiyama Castle served chiefly as a residential estate for the ruling Toki clan, who acted as the provincial governors of Mino. Its architectural style reflected its function as a dwelling rather than a military stronghold, utilizing the small hill more for status and residence than for strategic advantage against invading forces.

The castle holds significant historical importance due to its connection to the turbulent Sengoku period and the infamous Saitō clan. After the Toki clan lost influence, the warlord Saitō Dōsan seized control and occasionally used the site as an accessible refuge before moving his main power base to Inabayama Castle. Dōsan later granted the castle to his son, Saitō Yoshitatsu, in 1548. However, family discord soon turned deadly; fearing displacement by a younger brother, Yoshitatsu murdered his siblings, an act that triggered the Battle of Nagaragawa in 1556. This conflict resulted in Dōsan's death and the subsequent destruction of Sagiyama Castle, marking the end of its active use.

Today, the site is preserved as Sagiyama Park, where visitors can observe remaining earthworks, including low earthen ramparts and traces of ancient moats. Although large-scale civil engineering projects in 1964 for the Tōkaidō Shinkansen and Meishin Expressway quarried portions of Mount Sagi, reducing the hill's original size, the area remains a protected historic landmark. Excavations during these construction efforts uncovered foundation stones believed to be part of the original structures. A stone marker now stands near the summit to commemorate the castle's legacy, offering a tangible link to the region's feudal past amidst the modern landscape.