SilkCode LibraryCastles of Japan
No. 040Hokuriku & TokaiShizuoka

Yamanaka Castle

山中城

Ruins & historic sites

This Hojo stronghold guarded the Hakone route with earthworks rather than a monumental keep. Its patterned ditches reveal careful defensive design in a castle built largely from earth.

The grassy grid-like shoji-bori dry moats at Yamanaka Castle
The grassy grid-like shoji-bori dry moats at Yamanaka CastlePhoto: Mocchy at Japanese Wikipedia · Public domain · Resized and converted to WebP. Cards crop the display.This photograph shows the site at the time it was taken. Check the notes and official sources for current restoration work and access.

Get to know the castle

Castle at a glance

Site & layout
Mountain castle with earthen defences
Origins
Second half of the 16th century
Builders & patrons
The Later Hojo family
Other names
Yamanaka Castle ruins
What remains today
Enclosures, banks, grid-patterned and ridged ditches

THE STORY

The story behind the walls

The Later Hojo developed Yamanaka in the second half of the 16th century. It controlled the route across Hakone and helped defend Odawara. The castle fell to Toyotomi forces in 1590. Excavation and conservation have since made its distinctive ditch systems visible to visitors.

LAYOUT & ARCHITECTURE

Read the landscape and the buildings.

Enclosures follow the ridges and are protected by embankments and dry ditches. Ridges left inside the ditches restricted movement and footing. The maintained grass surfaces today should be distinguished from the depth and profile revealed by excavation.

A CLOSER LOOK

Details worth a closer look.

01

Grid-patterned ditches

Earthen ridges divide these ditches into compartments. From above, their grid pattern makes it easier to imagine the difficulty of crossing them.

02

Ridged ditches

Ridges within the ditches interrupted an attacker’s movement. They are defensive devices as well as striking shapes in the landscape.

03

Defending the Hakone route

The castle protected the western approaches to Odawara. Its position beside the mountain route explains why this location mattered.

THROUGH THE YEARS

A short timeline

  1. Late 16th century

    The Later Hojo developed the stronghold to defend the Hakone approaches.

  2. 1590

    The castle fell to Toyotomi forces.

  3. Modern period

    Excavation and conservation exposed the ditch systems.

BEFORE YOU GO

A note before you go.

View the protected ditches and banks from the paths. Earthen and grassy surfaces can be slippery after rain.

Official visitor information ↗Find it on a map ↗

Information checked: 27 September 2026

Sources & official information

Some official sources are available in Japanese only.

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