Nagashino Castle, Medieval fortress in Shinshiro, Japan.

Nagashino Castle is a medieval fortress in Shinshiro where stone walls and earthen ramparts rise at the point where the Toyokawa and Uren rivers meet. The site spreads across several levels with visible foundations of the main fortification and smaller defense lines.

Suganuma Motonari built Nagashino Castle in 1508 on a cliff above the Kansagawa and Uregawa rivers. In 1573 Tokugawa Ieyasu took it from the Suganuma and installed Okudaira Nobumasa. In 1575 Takeda Katsuyori besieged it with 15,000 men; Okudaira held with 500 until Tokugawa and Oda Nobunaga relieved the castle, and the defeat broke Takeda power.

The name Nagashino comes from the village that grew around the castle. The site is now a public park where the Shinshiro City Nagashino Castle Ruins Museum displays artifacts from the 1575 siege. A gate from the castle's Bansho enclosure survives at Momogyu-ji temple in Shinshiro, moved there through several relocations.

The site is a seven-minute walk from Nagashino-jo Station or about ten minutes by car from the Shinshiro interchange. Comfortable shoes are advisable because some paths cross uneven ground with slopes.

The Iida Line tracks now cut straight through the former castle grounds, separating the main fortification from the outer defense rings. Trains pass through the historic site several times a day, giving the place an unusual mix of past and present.