Hongo Haniwa Kiln Site is an ancient kiln complex in Hongo, Fujioka City, Gunma Prefecture, where haniwa clay figures were fired during the Kofun period (approximately the 3rd to 7th centuries). Designated as a National Historic Site of Japan, it is an important archaeological site for understanding how haniwa were produced in ancient Japan.
The surviving kiln remains are protected by a shelter, allowing visitors to see the archaeological remains in a condition close to that in which they were uncovered. For travelers interested in Japanese history and archaeology, the site offers a fascinating glimpse into ancient craftsmanship.
Two major centers of haniwa production are known in Gunma Prefecture: the Ota area and the Fujioka area.
Within the Fujioka area, the Hongo Haniwa Kiln Site along the Kanna River and the Saruta Haniwa Kiln Site along the Ayukawa River are particularly important. Archaeological investigations have confirmed that the Hongo kilns were in operation from the late 5th century through the end of the 6th century, making the site a major production center where haniwa were manufactured over an extended period.
The Hongo Haniwa Kiln Site was discovered in 1906 during road construction, when remains were exposed on a cut slope.
Investigations by archaeologist Shibata Jōe uncovered ash, charcoal fragments, fired earth, and pieces of haniwa, confirming that the location had once been used as a kiln for producing the clay figures.
More extensive excavations were carried out in 1943 and 1944. Two climbing kilns were discovered approximately 50 meters to the north. Known as Kiln A and Kiln B, both were large structures measuring approximately 10 meters in length and 2 meters in width.
More than 20 additional kilns may once have existed in the surrounding area, suggesting that the site was part of a substantial kiln complex dedicated to haniwa production.
One of the defining features of the Hongo Haniwa Kiln Site is its use of climbing kilns built into the sloping terrain of a river terrace along the Kanna River.
The kilns consisted of front and rear sections. The rear section was the firing chamber, built on a slope of approximately 30 degrees, while the front section served as the firebox.
The side walls and floor were carefully constructed from strong clay, demonstrating the sophisticated kiln-building techniques available in ancient Japan.
A wide variety of haniwa fragments have been discovered inside the kilns, including human figures, horse figures, and representations of weapons and other objects. These artifacts are thought to date mainly from the middle to latter part of the 6th century.
The presence of such a wide range of figurative haniwa suggests that the Hongo kilns were more than a small local workshop. They are believed to have been an important production center supplying haniwa over a relatively wide area.
High-quality clay deposits are found beneath the Fujioka Plateau, where central Fujioka is located. Similar clay layers are also present in the Hongo area and continue to be used as raw material for roof tiles today.
The combination of abundant clay resources and naturally sloping terrain made the area particularly well suited to haniwa production. Local access to raw materials was an important factor in the development of the kiln complex.
The Hongo Haniwa Kiln Site is located at the southern edge of the Kobayashi Kofun Cluster, raising questions about the relationship between the people buried in the ancient tombs and the groups of artisans who produced their haniwa.
Approximately 100 meters south of the kiln site stands Haji Shrine, dedicated to Nomi no Sukune, a legendary figure traditionally associated with the origins of haniwa.
Because Nomi no Sukune is closely associated with the Haji clan, traditionally linked to pottery and burial-related crafts, the site has prompted speculation that an artisan group sharing a connection with the Haji tradition may have worked in this area.
These connections provide an intriguing window into the social and religious world surrounding ancient haniwa production.
The Hongo Haniwa Kiln Site was designated a National Historic Site in 1944, and a protective shelter was constructed over Kiln A the following year.
Visitors can still observe the kiln structure at close range, making the site a valuable place to learn about ancient firing techniques and the production of haniwa.
Only a limited number of ancient haniwa kiln sites in Japan remain open to the public while preserving their archaeological features in a condition close to that of their excavation. The Hongo site therefore has considerable academic and historical value as a place where visitors can see the structure of an ancient haniwa kiln firsthand.
Hongo Haniwa Kiln Site is an important historic site that reveals how haniwa were produced during the Kofun period.
The combination of abundant clay resources, carefully designed climbing kilns, diverse haniwa production, nearby burial mounds, and the connection with Haji Shrine provides valuable clues to the technology, beliefs, and social organization of ancient Japan.
When visiting Fujioka City, take time to explore this quiet historic site and imagine the artisans who worked here more than 1,500 years ago. The preserved kilns offer a rare opportunity to connect with the craftsmanship, religious traditions, and local history of ancient Japan.