1,800 Volunteers Pull 400-Ton Hirosaki Castle Keep 7.5 Feet in Restoration Push

Q: What hidden secrets were unearthed beneath Hirosaki Castle while its 400-ton keep was temporarily moved for nearly a decade?

The temporary relocation of Hirosaki Castle’s 400-ton keep exposed previously hidden remains beneath the structure: traces of older stone walls, a well, and drainage facilities. These finds emerged during archaeological surveys carried out after the keep was moved in 2015 to allow repairs to the castle’s stone base, which had been damaged following a 1983 earthquake. Officials said the discoveries added complexity to the preservation work because they revealed earlier construction layers and infrastructure under the current foundation. The project has since involved carefully restoring the wall stones in their original positions while documenting the newly uncovered features. In practical terms, the “secrets” unearthed were not treasure or chambers, but important historical evidence showing how the castle site had been built, modified, and serviced over time.

3 articles · Updated · Smithsonian Magazine · Aug 27

1,800 lottery-selected volunteers pulled Hirosaki Castle’s roughly 400-ton keep 7.5 feet last weekend, marking a milestone in its return to the original site in Aomori Prefecture.
The move resumes a restoration project launched after long-standing concerns over damaged stone walls; the keep had been shifted 256 feet in 2015 so crews could repair the base and conduct archaeological work.
Rotating groups of about 80 people tugged nearly 100-foot ropes, moving the structure 4 feet on Aug. 22 and 3.5 feet on Sunday using the traditional hikiya roller method alongside machinery.
About 4,000 people are expected to help move the keep 16 feet by hand this month before machines handle the remaining 240 feet, with the structure due back on its base later this year.
Hirosaki Castle’s current three-story keep—one of Japan’s 12 surviving feudal-era castle towers—is expected to stay closed until 2033 as preservation work continues after the relocation.