Get to know the castle
Castle at a glance
- Site & layout
- Mountain castle ruins with substantial masonry
- Origins
- 1469; altered during the Sengoku period
- Builders & patrons
- Iwamatsu and Yokose-Yura families
- Other names
- —
- What remains today
- Enclosures, ditches, masonry and ponds
THE STORY
The story behind the walls
The castle was founded in 1469 as an Iwamatsu stronghold. It later belonged to the Yokose-Yura family and was altered during the wars of the Sengoku period. After Hojo control, it was abandoned in 1590. Excavation revealed extensive masonry and paving, making it important to research on Kanto mountain castles.
LAYOUT & ARCHITECTURE
Read the landscape and the buildings.
The design combines ridges and steep slopes with enclosures, cut ditches and entrances. Masonry and paving were used extensively at key defensive points. Conserved archaeological features reveal how builders combined earth and stone.
A CLOSER LOOK
Details worth a closer look.
Main entrance defences
The stone-faced, paved entrance is a major feature. Changes of direction and overlooking positions help explain its defensive purpose.
Sun and Moon ponds
The Sun and Moon ponds introduce the question of water supply and use within a mountain castle. Their relationship with the stone-built areas is distinctive.
Ridge enclosures
Several enclosures follow the ridges. The visit is about reading controlled routes and defended spaces rather than reaching a single tower.
THROUGH THE YEARS
A short timeline
- 1469
Kanayama Castle was founded.
- 16th century
The Yura and other rulers altered the castle.
- 1590
Abandoned at the time of the Hojo defeat.
BEFORE YOU GO
A note before you go.
Expect mountain paths and stone steps. Check weather and Ota City’s current access information, including the guidance facility’s opening arrangements.
Information checked: 27 September 2026
Sources & official information
Some official sources are available in Japanese only.
