Yoshinogari Ruins

The Yoshinogari Ruins are located on the Yoshinogari Hills, which straddle Yoshinogari Town (Kanzaki District) and Kanzaki City in Saga Prefecture. They are among the most representative moat-settlement ruins of the Yayoi period in Japan. Today, they are designated as a Special Historic Site of the nation and are partially open to the public as the Yoshinogari Historical Park. The ruins cover an area of about 117 hectares. Since excavations began in 1986, they have gradually revealed important aspects of ancient Japanese society.

From the eastern part of Saga Prefecture, the terrain descends from the approximately 1,000-meter-high Sefuri Mountains in the north to the hilly regions at the southern foot of the range, continuing down into the Saga Plain and toward the Ariake Sea. The Yoshinogari Hills form part of these southern foothills of the Sefuri Mountains, extending across Yoshinogari Town (formerly Mitagawa Town) and Kanzaki City (formerly Kanzaki Town).

The most notable feature of the Yoshinogari Ruins is the remains related to settlement defense. In the late Yayoi period, double moats consisting of outer and inner moats were constructed. The V-shaped outer moat stretches about 2.5 kilometers in total length, enclosing an area of approximately 40 hectares. Defensive facilities such as wooden palisades, earthen embankments, and gyakugi (inverted wooden stakes used to block intruders) were built along the moats. Watchtowers were also set up inside the moats for surveillance and to intimidate enemies. Within the large outer moat, there were two inner moats, around which many structures were clustered. The northern settlement has been named the “Northern Inner Enclosure” (Kita Naikaku), while the southern one is called the “Southern Inner Enclosure” (Minami Naikaku).

Inside and outside these inner enclosures, building remains have been found, including pit dwellings and raised-floor buildings. It is believed these were the residences of ritual specialists and their attendants. Within the enclosures, ritual buildings such as the main sanctuary, the eastern sanctuary, and purification halls were discovered. In addition, raised-floor storehouses for grain storage, storage pits, and evidence of bronze-casting facilities have been uncovered.

A large number of burials have also been found, including jar coffins, stone coffins, and pit graves used for collective interments, thought to be the burial grounds for common residents and soldiers. At the north and south ends of the site stand two burial mounds, named the “North Burial Mound” and the “South Burial Mound,” believed to be tombs of settlement leaders. Some jar coffins contained human remains with wounds, arrowheads still embedded in their bodies, or decapitated skeletons, testifying to the brutality of warfare and evoking the turbulent period known as the “Great Disturbance of Wa.” Other graves contained decorative objects such as glass tubular beads and ornaments.

Artifacts unearthed include large quantities of pottery, stone tools, bronze implements, ironware, and wooden objects. Personal ornaments such as magatama and tubular beads, bronze swords, bronze mirrors, textiles, and ritual items have also been discovered. In 1998, a bronze bell (dōtaku) was unearthed near the site. Believed to have been produced in northern Kyushu, it is classified as the “Fukuda type dōtaku” based on its shape.

These remains and artifacts not only show features common to northern Kyushu and other regions of Japan but also exhibit many similarities with those of mainland China, the Korean Peninsula, and the Ryukyu Islands.

Additionally, three keyhole-shaped tombs (zenpō-kōhō-fun) within the site are believed to have been constructed after the Yayoi settlement itself had disappeared.