Sanada Maru

Sanada Maru was a small earthwork fortress attached to the southeast side of Osaka Castle, made from mounded earth and wooden walls with firing platforms for cannons and muskets. The structure included gates, moats and wooden barriers that formed a compact defensive enclosure facing the most vulnerable approach to the main castle.

Sanada Nobushige built the fort during the winter of 1614 to defend the weaker southern side of Osaka Castle against the advancing Tokugawa army. After weeks of heavy fighting, the structure was dismantled as part of the peace agreement that followed the siege.

The fortification design reflects Japanese military architecture of the early 17th century with strategically positioned walls and observation points for defenders.

The site lies near Myojo Gakuen school and on a slight elevation that once offered a clear view of the surrounding area. Markers and models on site explain the original layout and defensive strategy used during the siege.

Legends speak of secret tunnels connecting the fort to the main castle, though historians doubt their existence and believe they were later stories. Defenders dug mines beneath the earth walls to counter enemy attacks with underground explosions.

Location: Esashi-machi

GPS coordinates: 34.67286,135.52628

Latest update: December 5, 2025 08:05