Mizuki

Mizuki is an ancient fortification in Fukuoka Prefecture, Japan. The earthwork structure extends for about 1.2 kilometers and reaches a height of roughly nine meters in some sections.

The site was built in 664 on the order of Emperor Tenchi as a defensive line following conflicts with the Korean kingdom of Baekje. Construction came soon after the Battle of Baekgang River and was meant to protect the capital from possible attacks.

The name comes from an old Japanese term referring to a water-related fortification. The visible earthen walls still show the layered construction method where plants were used to stabilize the soil.

The ruins are about 25 minutes on foot from Tofuromae Station on the Nishitetsu Tenjin Omuta Line. The walk passes through quiet residential neighborhoods and slopes upward gradually, so sturdy shoes help.

Archaeological digs brought to light pottery fragments from the 8th century bearing the site's name in old Japanese script. These finds provided proof of the place's historical identity and helped clear up centuries of uncertainty.

Location: Fukuoka Prefecture

Inception: 664

Part of: Continued Top 100 Japanese Castles

GPS coordinates: 33.51810,130.49280

Latest update: December 5, 2025 22:24