Koiwatake Castle

Koiwatake Castle sits on a forested hillside with stone fortifications arranged across multiple defensive levels. The site includes rebuilt structures such as a gateway and watchtower that serve as viewing points for exploring the grounds.

The castle was founded in 1522 by Nishina Morikuni and faced a major assault by 3000 soldiers under Takeda Shingen in 1552. The defenders, numbering roughly 500, held the position during this three-month siege.

The site displays Japanese fortification methods with large natural boulders that form defensive terraces woven into the mountainside. Visitors can observe how the layout used the terrain to slow attackers and advantage defenders.

Visit during warmer months when the paths are dry and easy to navigate. Wear sturdy footwear since the terrain is hilly and uneven throughout the site.

A cave beneath one of the natural rock boulders at the site was used as a storage area during the castle's operational years. This hidden feature reveals how defenders cleverly incorporated the landscape into their security plans.

GPS coordinates: 36.35581,137.82844

Latest update: December 13, 2025 11:44