Sannai-Maruyama: Large Jōmon Settlement in Northern Japan

Sannai-Maruyama is the site of a large prehistoric village in Aomori City, at the northern tip of Japan’s main island of Honshu. Occupied from about 3900 to 2200 BC during the Early and Middle Jōmon periods, it contained hundreds of pit houses, large communal buildings, organised cemeteries and a massive timber structure set on six giant posts. Its excavation in the 1990s transformed the picture of the Jōmon people as small, wandering bands.

The Jōmon world

The Jōmon period is the long prehistoric era in Japan that began more than 15,000 years ago with some of the world’s earliest pottery and lasted until rice farming spread from about 1000 BC onwards. The name means “cord-marked”, after the twisted-cord impressions on its pottery. Jōmon people lived mainly by hunting, fishing and gathering, but many of them settled in permanent villages long before agriculture.

Northern Japan, with its rich forests, rivers and seas, was especially suited to this way of life. Sannai-Maruyama sits on a terrace above the Okidate River, a few kilometres from Aomori Bay, giving access to both forest and marine food. For a broader view of the period, see Jōmon culture.

Discovery and excavation

The site had been known since the Edo period, when local writers described finds of pottery and clay figures. Small excavations took place in the 20th century, but its full size was not appreciated.

In 1992 Aomori Prefecture began a large rescue excavation before building a baseball stadium on the land. Over the next two years archaeologists uncovered far more than expected. In 1994 they found six enormous post holes holding the remains of chestnut-wood posts, along with evidence of dense housing, burials and refuse mounds.

Public interest was intense. In 1994 the prefecture cancelled the stadium project and decided to preserve the site. It was designated a Special Historic Site of Japan in 2000, and a museum and reconstructed village now present it to visitors.

Layout of the village

Sannai-Maruyama was not a random cluster of huts. Over the centuries it developed a planned layout that included:

• Pit dwellings: more than 700 have been identified, though only a fraction stood at any one time. They were round or oval houses dug partly into the ground and roofed with thatch, bark or earth.
• Large longhouses: several large buildings, the biggest about 32 metres long, may have been meeting halls, workshops or communal winter houses.
• Raised-floor buildings: clusters of post holes suggest buildings with floors raised above the ground, perhaps for storage.
• Burial areas: adults were buried in pits arranged along both sides of a road leading out of the village, while hundreds of infants and young children were buried in pottery jars.
• Mounds: large heaps of soil, broken pottery, stone tools and other debris built up over long periods and may have had ritual as well as practical roles.

The six-pillar structure

The most famous feature of the site is a group of six post holes arranged in two rows of three. Each hole is about 2 metres wide and 2 metres deep, and they are spaced about 4.2 metres apart. The bottoms of the chestnut posts survived in the waterlogged soil, each around 1 metre in diameter.

The precise spacing suggests the builders used a standard unit of measurement. What the posts supported is unknown. The structure might have been a watchtower, a ritual platform, a roofed building or simply free-standing pillars. The reconstruction at the site shows a tall open tower about 15 metres high with three platforms, but this is only one possibility, and some scholars think it was roofed.

Food, plants and trade

Excavations recovered huge amounts of plant and animal remains, preserved in waterlogged deposits. People ate fish such as mackerel, sea bream and flatfish, hunted hares and flying squirrels, and gathered walnuts, horse chestnuts and sweet chestnuts.

Chestnuts were especially important. Pollen studies show that chestnut trees dominated the surrounding woodland while the village was occupied, and genetic analysis of chestnut remains suggests that the trees were selected and managed. People also used bottle gourds, beans and burdock, a form of plant management between foraging and farming.

The villagers obtained materials from far away. Jade, a green stone called hisui in Japanese, came from the Itoigawa area on the Sea of Japan coast, hundreds of kilometres to the south-west. Obsidian came from Hokkaido and other sources, and amber from the Pacific coast of northern Honshu. Natural asphalt was used to fix arrowheads to shafts.

Crafts and ritual objects

The site has produced vast quantities of pottery, including tall cylindrical vessels typical of northern Japan. Lacquered wooden bowls, woven baskets and textiles of plant fibre show advanced craft skills.

Large numbers of clay figurines known as dogū were found, most of them flat, cross-shaped figures with simple faces. They are usually interpreted as ritual objects, perhaps linked to fertility, healing or protection, but their exact meaning is unknown. Stone rods, ear ornaments and beads complete the picture of a rich ritual and decorative life.

Life through the seasons

The rich food remains allow archaeologists to reconstruct the yearly cycle at Sannai-Maruyama. Spring and summer brought fish and shellfish from the bay and rivers, while autumn was the season for nuts, the most important stored food. Pits and raised-floor buildings may have held chestnuts and walnuts through the long, snowy winters of northern Honshu.

Villagers also made clothing and containers from plant fibres. Fragments of woven bags, including a small basket nicknamed the “Jōmon pochette”, show fine twining techniques. Bone needles and fish hooks, stone axes for woodworking and grinding stones for processing nuts complete the toolkit. Together these finds show a community that knew its environment intimately and planned ahead for lean times.

How many people lived there?

Early reports in the 1990s suggested that up to 500 people might have lived at Sannai-Maruyama at its peak. Later studies, taking into account that houses were built and abandoned over many centuries, generally give lower figures, perhaps in the order of a few hundred at most and often fewer. The population probably rose and fell over the long life of the village. Estimates depend on how many houses are thought to have been in use at the same time, a question that radiocarbon dating cannot answer precisely, so any figure should be treated as approximate.

Around 2200 BC the settlement declined and was abandoned. A cooling climate and changes in food resources are often suggested as causes, but the evidence is not conclusive.

Timeline

• c. 3900 BC: Settlement begins at Sannai-Maruyama in the Early Jōmon period.
• c. 3000–2500 BC: The village reaches its greatest extent in the Middle Jōmon period.
• c. 2200 BC: The settlement is largely abandoned.
• 1992: Large-scale rescue excavation starts before planned stadium construction.
• 1994: The six-pillar post holes are found; the stadium plan is cancelled.
• 2000: The site is designated a Special Historic Site of Japan.
• 2021: Sannai-Maruyama is inscribed on the UNESCO World Heritage List as part of the Jōmon Prehistoric Sites in Northern Japan.

Why it matters

Sannai-Maruyama showed that people without agriculture could build large, long-lived and carefully organised communities. Its timber structures, cemeteries, long-distance trade and managed chestnut groves make it one of the most important sites for understanding how foragers created complex societies, a story usually told only for early farmers at sites such as Çatalhöyük in Anatolia.