Omori Katsuyama Stone Circle
Omori-Katsuyama Iseki · Ōmori Katsuyama
Late Jomon (2000–1000 BCE)·Late Jomon (Tsugaru–Iwaki region)·🇯🇵 Aomori Prefecture, Hirosaki City, foot of Mt. Iwaki (Tsugaru plain west), Japan
About
About Omori Katsuyama Stone Circle
Late Jomon double stone circle (c.2000–1500 BCE) at the foot of Mt. Iwaki near Hirosaki, Aomori — two concentric andesite rings 48 m and 29 m diameter, with 77 standing stones up to 1.5 m high encircling a central 2 m monolith, excavated 1998–2006. Omori Katsuyama is the westernmost Jomon stone circle in Aomori, showing Iwaki volcanic stone transport 10 km and Jomon astronomical orientation (midwinter sunset through monolith gap); UNESCO Jomon component (1632-016) with best-preserved Tsugaru standing stones.
Why it mattersWesternmost Aomori stone circle; proves Iwaki stone long-distance transport and Jomon mountain cosmology.
Open questions
Mysteries & theories
Mysteries
- 01Is central monolith Mt. Iwaki effigy — mountain worship?
Theories
- 01Tsugaru winter-solstice mountain alignment model
Theories are interpretations, not findings. The seal above tells you how much scholarly weight the place carries.
History
How it came to be
- Built
- c.2000 BCE (outer 48 m); inner 29 m c.1700 BCE
- Period
- Late Jomon (2000–1000 BCE)
- Culture
- Late Jomon (Tsugaru–Iwaki region)
- Builders
- Jomon communities (Iwaki foothill)
- Purpose
- Ritual stone circle and mountain-viewing cosmology center
- Abandoned
- c.1000 BCE
- Rediscovered
- 1998 Hirosaki City excavation
- Excavation
- Excavated
c.2000 BCE
Outer 48 m circle with 77 andesite standing stones erected
c.1700 BCE
Inner 29 m circle and 2 m central monolith added
2021
UNESCO Jomon Prehistoric Sites 1632-016 inscription
On the ground
Structures & features
40.6983° N · 140.3583° E · 80 m · 2 mapped features
Outer 48 m stone ring
stone circle77 andesite standing stones 0.8–1.5 m encircling outer ring
40.6985° N · 140.3581° ECentral monolith and inner circle
stone circle2 m central monolith within 29 m inner ring
40.6982° N · 140.3585° E