Isawa Castle

Isawa Castle is a Japanese fortress ruin in Ōshū that occupies a large site with double moats and earthen walls. The central administrative area was surrounded by fortified barriers and formed the core of the military compound.

Sakanoue no Tamuramaro established the fortress in 802 as a headquarters for military control of the northern territories. The compound remained operational for a century and a half before being abandoned during the Later Three Years War.

The fortress takes its name from the early Heian period administration of Japan's northern regions. Visitors today can see reconstructed gates and earthworks that show how the military compound originally appeared.

A historical park has been developed on the castle grounds, showing ancient fortification methods with reconstructed gates and earthworks. The site is accessible to the public and gives a sense of how Japanese fortresses were built in the early medieval period.

Archaeologists found wooden tablets and lacquered papers on the site that give insight into the administration of an early medieval military post. These documents also reveal calendars used by the soldiers stationed there.

Location: Oshu

GPS coordinates: 39.17973,141.13500

Latest update: December 5, 2025 22:26