Matsushiro Castle Ruins, Nagano

Matsushiro Castle, also known as Kaizu Castle, was built in 1560 by the warlord Takeda Shingen as a strategic stronghold during Japan's Sengoku period. Following the fall of the Takeda clan, the castle came under the control of the Sanada clan, who governed the Matsushiro domain for 250 years until the Meiji Restoration in the late 19th century. The castle was largely dismantled during the Meiji era, leaving behind the stone walls, moats, and earthworks that define the site today.

The ruins are designated as a National Historic Site of Japan, recognized for their well-preserved layout that illustrates classic flatland castle architecture. Unlike mountain fortresses, Matsushiro was built on level ground and relied on an intricate system of water moats and earthen embankments for defense. The site offers a rare and largely unaltered example of how such castles were engineered during the feudal period. In spring, the grounds attract visitors for their cherry blossoms, which frame the stone bridges and moats in a setting that has changed little in centuries.

Visitors can walk the perimeter of the reconstructed Taiko-mon Gate and Higashi-Nagaya turret corridor, which were carefully rebuilt based on historical records. The surrounding moats remain filled with water, and the interior grounds are open parkland where the foundations of the main keep are still visible. The Sanada Treasure Museum and the historic Sanada Residence are located nearby, making Matsushiro a self-contained district for exploring the region's samurai heritage.

Matsushiro is located approximately 13 kilometres south of central Nagano City. From Nagano Station, the site is accessible by bus via the Matsushiro-bound route (川中島バス), with a journey time of around 40 minutes. Alternatively, the site is about a 25-minute drive by car or taxi. Admission to the castle grounds is free, though entry to associated museums such as the Sanada Treasure Museum carries a separate fee of around ¥500–¥600 per adult.