Kokufu Ruins

The Kokufu Site: A Terrace Where 20,000 Years of Life Overlap

On a low terrace in the Sōja district of Fujiidera, just west of the point where the Ishikawa River joins the Yamato River, lies a patch of ground that people never really abandoned. The Kokufu Site (Kō Iseki) holds traces of human activity running from the last Ice Age to medieval times, layer upon layer in the same soil. In 1917 it became the place where Japanese archaeology ran its first scientific excavation, and the discoveries made here have kept the site at the center of academic debate ever since.

Today much of the ground is quiet. A neighborhood park covers part of it, with a stone monument and a flowerbed that most passers-by would not connect to anything unusual. The interest of the place is almost entirely beneath the surface, and in what that surface once gave up.

A Settlement Used Across Many Eras

The site sits on the northeastern edge of the Habikino terrace, near the confluence of two rivers and along routes that carried traffic across the Kawachi plain for centuries. That position helps explain why it was occupied for so long.

Roughly 20,000 years ago, Paleolithic toolmakers worked here, shaping stone into cutting edges. In the Jōmon and Yayoi periods the place became a village and a burial ground. In the Asuka period a Buddhist temple was built on the spot. By the Nara and Heian periods, the ground held the kokufu, the provincial government seat of Kawachi Province, which is the source of the modern place name. Archaeologists describe Kokufu as a complex site, meaning one where remains from several distinct periods sit stacked together rather than spread across separate locations.

The first organized digging came in 1917, the sixth year of the Taishō era. The year before, the historian Kita Sadakichi had drawn attention to large, coarsely worked stone tools collected here, and wondered whether they might predate the Jōmon period. Hamada Kōsaku of Kyoto Imperial University then excavated to test that idea by checking which geological layer the tools came from. His team instead found three well-preserved human skeletons close to the surface, and the focus of the work shifted toward the burials. Around ten excavations followed through 1921, and more than thirty have taken place across the site's history.

Why the Site Was Designated

The national government designated Kokufu a Historic Site on 25 June 1974, with an additional designation on 19 July 1977. The protected area covers about 18,450 square meters. The designation rests not on a single monument but on the unusual range of evidence the ground has produced.

One thread is the question of the Japanese Paleolithic. When Hamada dug in 1917, the prevailing view held that Japan had no Paleolithic past at all. The 1917 results were read as inconclusive on that point, and serious Paleolithic research stalled until the Iwajuku Site in Gunma was found in 1949. Reexcavation at Kokufu in 1957 and 1958 settled the matter locally: sanukite stone tools were confirmed in a clay layer below the Jōmon cultural layer, proving Ice Age occupation here.

A second thread is a specific stone tool. The "Kō-type knife-shaped tool" takes its name directly from this site. It was made using what is now called the Setouchi technique, a distinctive method of striking long, wing-shaped flakes from a core of sanukite, a fine-grained volcanic rock quarried near Mount Nijō. Because the type is so consistent and recognizable, archaeologists use it as an index marker for classifying and dating late Paleolithic stone-tool assemblages across western Japan.

A third thread is the human remains. Excavations recovered the skeletons of about 90 individuals from the Jōmon and Yayoi periods, a rare concentration in western Japan, where acidic soils and the scarcity of shell mounds usually destroy old bone. Some of these people were buried wearing slit-stone earrings, ring-shaped ornaments with a single cut, known as ketsujō earrings. Several skeletons show deliberate body modification: tooth ablation, the ceremonial removal of healthy teeth, and forked tooth filing, in which the upper front teeth were notched into prongs. Kokufu is the site from which forked tooth filing was first scientifically reported, and the finds remain key evidence for Jōmon social custom and ritual.

Most of the artifacts from the Taishō-era digs entered the collection of Motoyama Hikoichi, owner of the Osaka Mainichi Shimbun, which had funded the work. That material now forms the Motoyama Collection at the Kansai University Museum, and part of it is designated an Important Cultural Property in its own right.

What You Can See on the Ground

A visitor expecting reconstructed buildings will not find them. Kokufu is a site to read rather than to look at, and a little background changes the experience considerably.

Within the protected ground stands the foundation stone of a pagoda. It belonged to a temple that local people came to call the Inui temple, after the old field name for the spot. Roof tiles excavated here were made from the same molds used at Asuka-dera, Japan's oldest full-scale Buddhist temple, which dates the founding of the Inui temple to the early seventh century. The stone is the most tangible survival of that Asuka-period building.

A flowerbed on the site marks the area where the Jōmon and Yayoi burials were found, a quiet way of showing where the cemetery once lay. A stone monument records the site's status. Visitors interested in the slit-stone earrings will recognize their shape elsewhere in the city without realizing it: the emblem of Fujiidera combines the outline of a keyhole-shaped tomb with the form of a ketsujō earring excavated here, so the city carries a piece of the site in its official mark.

Standing on the terrace, it is worth picturing the sequence: toolmakers at the end of the Ice Age, a Jōmon village burying its dead with care, a seventh-century temple, and the offices of a provincial government, all on the few hundred meters of ground beneath your feet.

Getting There and Nearby Sites

The site is a walk of about 10 minutes northeast from Haji-no-sato Station on the Kintetsu Minami-Osaka Line. There is no parking, and the surrounding lanes are narrow, so public transport is the practical choice. The grounds are open space with no admission fee or fixed hours.

Kokufu sits in one of the densest concentrations of ancient sites in Japan. Just to the southwest is Ichinoyama Kofun, a large keyhole-shaped tomb traditionally identified as the tomb of Emperor Ingyō and part of the Mozu-Furuichi Kofun Group, inscribed on the UNESCO World Heritage List. About 870 meters away stand Dōmyōji Tenmangū, a shrine associated with the scholar-official Sugawara no Michizane, and the neighboring Dōmyōji temple. Combining the Kokufu Site with these places makes for a half-day route through several layers of the region's past.