Special Thematic Exhibition
Before the Jōmon Era
Commemorating 80 Years Since the Discovery of Japan's Paleolithic Period

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Stone Spear Point
Stone Tools Collected at the Iwajuku Site, Midori, Gunma（Aizawa Tadahiro Collection）, Upper Paleolithic period, 23,000 BC, Iwajuku Museum, Gunma (Registered Tangible Cultural Property)

Japanese Archaeology and Special Exhibition (Heiseikan) Thematic Exhibition Room
June 16, 2026 (Tue) - August 23, 2026 (Sun)

2026 marks 80 years since the discovery of Japan’s Paleolithic period. In 1946, Aizawa Tadahiro from Kiryū, Gunma Prefecture, discovered some stone tools at Iwajuku (modern-day Azami, Kasakakemachi, Midori, Gunma). This led to a full-scale survey by a team of archaeologists from Meiji University over 1949-50. The results revealed how Japan’s prehistory actually stretched back beyond the Jōmon period to a time before people used pottery.

By proving the existence of a Paleolithic period in Japan, the Iwajuku findings marked a major breakthrough in the field of archaeological research.

This exhibition explores Japan’s Paleolithic culture through items collected by Aizawa Tadahiro and objects found at the Iwajuku site. It also displays Paleolithic materials from the rest of the world that were referenced by researchers who took part in Japan’s first Paleolithic excavation. We hope the exhibition provides a valuable opportunity to learn more about the Paleolithic period.

（Left）

Stone Spear Point

Stone Tools Collected at the Iwajuku Site, Midori, Gunma（Aizawa Tadahiro Collection）
Upper Paleolithic period, 23,000 BC
Iwajuku Museum, Gunma
(Registered Tangible Cultural Property)

（Right）Aizawa Tadahiro
Image courtesy of the Iwajuku Museum, Gunma

Major works in this exhibition

Chapter One: On the Eve of the Iwajuku Findings

Stone Tools Collected at the Iwajuku Site

Surface collection; Iwajuku Site, Midori, Gunma（Aizawa Tadahiro Collection）
Upper Paleolithic period, 35,000-16,000 BC
Iwajuku Museum, Gunma
(Registered Tangible Cultural Property)

Chapter Two: The Iwajuku Survey and the Discovery of a "Japanese Paleolithic Period"

Stone Tools Excavated from the Iwajuku Site（Iwajuku Ⅰ Culture）

Excavated from the Iwajuku Site, Midori, Gunma
Upper Paleolithic period, 35,000 BC
Meiji University Museum, Tokyo
(Important Cultural Property)

Stone Tools Excavated from the Iwajuku Site（Iwajuku Ⅰ Culture）; Axe

Excavated from the Iwajuku Site, Midori, Gunma
Upper Paleolithic period, 35,000 BC
Meiji University Museum, Tokyo
(Important Cultural Property)

Chapter Three: Japan's Paleolithic Culture

Stone Tools Excavated from the Motojuku Site; Stone Spear Point

Excavated from the Motojuku Site, Kiryú, Gunma
Upper Paleolithic period, 18,000 BC（Aizawa Tadahiro Collection）
Iwajuku Museum, Gunma
(Registered Tangible Cultural Property)

Stone Tools Excavated from the Masugata Site; Microblade and Microblade Core

Excavated from the Masugata Site, Maebashi, Gunma
Upper Paleolithic period, 16,000 BC
Iwajuku Museum, Gunma
(Registered Tangible Cultural Property)

Chapter Four: Paleolithic Cultures Across the World

Handaxe
Surface collection; Saint-Acheul Site, Somme, France
Lower Paleolithic period, 450,000-350,000 BC
Tokyo National Museum

Cleaver
Surface collection; India
Lower Paleolithic period, 1.5 million-200,000 BC
Tokyo National Museum

Chapter Five: Reproducing the Paleolithic Period

Replicas of Hunting Tools
Modern-day
Iwajuku Museum, Gunma

Implements for Making Stone Tools
Modern-day
Iwajuku Museum, Gunma

Iwajuku Site Diorama
Modern-day
Iwajuku Museum, Gunma

Leaflet