柳川・吉野ヶ里・熊本の山間部Yanagawa, Yoshinogari, and the Mountains of Kumamoto

Today I am traveling through Yanagawa, Yoshinogari, and the mountainous regions of Kumamoto. Yanagawa City in Fukuoka Prefecture, known as the “city of water,” is a small town generally thought of as a land abundant in water resources. However, historically Yanagawa was not rich in water; rather, the opposite was true, as this entire area was a wetland environment. For more than a thousand years, people devised ways to secure fresh water and to live in a land with poor drainage in order to survive. The culmination of this long history, together with the accumulated wisdom of the people of the land and their continuous ways of living, has shaped the Yanagawa of today, making it essentially a cultural heritage site that embodies the history of those who lived here.

For example, during this journey, some of the areas originally planned for investigation, such as parts of Itoshima and the region from Kumamoto to Miyazaki, have become inaccessible due to landslides and other damages caused by heavy rains earlier this month, requiring flexible adjustments to the itinerary. In contrast, Yanagawa demonstrates a unique appeal in that it shows no trace of such damage. The water channels that run through the city incorporate an ancient wisdom called horiwari (堀割), and within this small area alone there are 1,100 sluice gates installed. These were built during the Edo period as part of town planning, representing the culmination of efforts to answer the question: “How do we secure water and connect it to daily life?” After the modernization of the Meiji era, an advanced system has been maintained even today, using radar and sensors to adjust the water level as needed. As a result, while other parts of Kyushu have been struck by torrential rains that disrupted people’s lives, Yanagawa has remained unaffected, preserving its calm landscape. During the Doll Festival and the cherry blossom season, the town overflows with tourists to the point of overtourism, but during other times it is relatively quiet and serene.

From Yanagawa, I visited Saga Prefecture’s representative site, the Yoshinogari archaeological site, for the first time in several years. Since its discovery in the 1980s, Yoshinogari has had a revolutionary impact on Japanese history and has played a pioneering role in archaeology as people sought to understand the Yayoi period. The people who built their base at Yoshinogari, which developed greatly during the mid-Yayoi period, created a vast settlement structure fortified with moats called kango (環濠), demonstrating unique national power. Because this large-scale Yoshinogari settlement closely resembled the technologies described in the Wajinden (魏志倭人伝), it fueled arguments that it was the country ruled by Himiko of Yamatai. At the same time, however, excavations at Yoshinogari also revealed that the Wajinden did not necessarily describe ancient Japan with accuracy. For instance, according to the records, the people of Yamatai wore simple clothing, but textiles discovered at Yoshinogari show complex weaving techniques, revealing a major discrepancy.

The sacred areas of Yoshinogari, where rituals were held, were distinct spaces reserved as special by the people of that time. Intriguingly, the top of the main shrine was adorned with motifs of boats and the birds guiding them. Bird motifs appear throughout the gates and facilities of Yoshinogari, and this is a significant characteristic also found among artifacts from other Yayoi sites across Japan. Some Yayoi pottery depicts priestesses dressed in bird-like garments on boats being guided by birds, symbolically showing birds steering vessels across the sea. This strongly suggests that they represented the ancestral memory of peoples who had crossed the Sea of Japan to arrive here. Given how widespread such motifs are, it seems clear that these settlements were built on exchange across the sea.

The highest-level rituals took place in the third tier of the shrine. Here, the priestess, the medium who entered a trance to commune with the divine, was accompanied by a musician playing a koto, while a man stood by her side to receive and relay her divine words. The mirror, beads, and sword used in these ceremonies were sacred ritual tools enabling communication with the divine, with assistant priestesses supporting her in the background. This structure matches the accounts of rituals at Himiko’s shrine, where Himiko herself would enter a trance and her words were conveyed by a male relative, often said to be her brother, thus linking divine possession with political authority. In this sense, Himiko was not only the absolute ruler in Yamato but also a symbolic figure of a complex tribal confederation, with priestesses leading ritual groups across the regions. Many of them had ties to Northeast Asia, formed through exchange across the sea.

Nevertheless, even this vast Yoshinogari settlement began to decline suddenly with the arrival of the Kofun period, and ultimately perished, taking considerable time to revive again in the late Kofun period. This suggests that an upheaval large enough to redraw the map of power across the archipelago took place at the end of the Yayoi period. In fact, excavations have uncovered the skeletons of people who died from battle wounds, and headless remains, traces of the turmoil of war. The forces at work, in exchange and conflict across the sea, were strong enough that even this major center could not hold. The rising power eventually made its base in Yamato. Evidence shows that many Yayoi settlements from Yoshinogari to Yamato were abandoned, with people moving to highland fortified villages surrounded by defensive walls, preparing for intrusions. Thus, the map of power on the plains changed completely, leading Japan into a new age in which Yayoi traditions gradually took on other forms.

The highest ritual leaders of Yoshinogari essentially lived within the sacred precincts, rarely appearing before ordinary people. Inside the sacred area stood stilted buildings, which, unlike the usual storage granaries, were square in shape and believed to be the residences of the highest priests. These were cut off from the outside world, with no windows to admit light, so even during the day they were likely illuminated by lamps. This preserved a rare custom that connects both to China and ancient Japan, showing the important characteristics of Yayoi priestess culture.

On the eastern side of the sacred area was the “East Shrine,” aligned with the sunrise of the summer solstice and the sunset of the winter solstice, considered an important facility for seasonal rites. Traces of repeated rebuilding have been found here, suggesting that structures were reconstructed with each ritual, a practice reminiscent of the shikinen sengu (式年遷宮) at Ise Grand Shrine and Izumo Grand Shrine, intended to renew the sacred power of the rites.

North of the sacred precinct, a burial mound called the “North Mounded Tomb” was constructed. Here the tombs of successive chiefs were placed together with grave goods such as glass beads and bronze artifacts, which testify to interactions with the Korean Peninsula and Northeast Asia, further confirming the presence of migrant peoples. The northward orientation of these tombs reflects an ideology of worshiping ancestors in the “north.” However, this must be understood in terms of the Yayoi concept of directions, where the sound nishi (ニシ) referred to what we call “north” today. The Wei envoys misunderstood this and assumed nishi meant west as in modern usage, which led to confusion in the Yamatai debate. In fact, for the Yayoi people, the north (nishi, inishi) was the direction of ancestral origins and their homeland.

Burial practices of the mid-Yayoi period developed into mounded tombs, which then spread across the land. The Yoshinogari settlement’s layout is especially notable: the northern tombs, the southern ritual spaces, and the main shrine on their axis aligned in a north–south line, with Mount Unzen located about 60 kilometers to the north. This arrangement symbolically linked ancestral worship with nature reverence, showing that the central shrine was a place connecting ancestors and nature. Pillars and ritual halls were erected in front of the tombs, and many ritual vessels have been excavated, underscoring its role as a center of ancestral worship.

Over 3,000 jar burials have been identified in the Yoshinogari burial grounds, with more than 1,000 belonging to the mounded tombs. These were aligned in two rows facing north, grouped by kinship units. In some cases, stone coffin burials and earth-pit burials were also found, showing the coexistence of different tribal groups. Grave goods included many glass beads and ornaments, confirming active trade with East Asia. These finds strongly support the view that the Yayoi people had their roots in Northeast Asia and developed a distinct cultural sphere different from the preceding Jomon culture and the subsequent Kofun culture.

In this way, the lessons Yoshinogari offers us are immeasurable. It is clear that Yoshinogari is an indispensable site for understanding the Yayoi period, an extremely complex and difficult age in Japanese history.