Sannai-Maruyama Site

At the Sannai-Maruyama Site, excavations that began in 1992 revealed the remains of a large settlement from the early to middle Jomon period (approximately 3,900–2,200 BCE; about 5,900–4,200 years ago). In addition to many pit dwellings, raised-floor buildings, earthen mounds, and graves for both adults and children, a large quantity of pottery and stone tools, as well as valuable wooden and bone/antler artifacts, were unearthed.

Because of the site’s importance, Aomori Prefecture decided in 1994 to preserve it. From 1995, the site was developed and opened to the public; in March 1997 it was designated a Historic Site, in November 2000 it became a Special Historic Site, and in May 2003, 1,958 excavated artifacts were designated Important Cultural Properties. In July 2021, the “Jomon Prehistoric Sites in Northern Japan,” including the Sannai-Maruyama Site, were inscribed on the UNESCO World Heritage List.

Aomori Prefecture will continue its efforts to preserve, develop, and make use of the Sannai-Maruyama Site as a place where visitors can experience a Jomon-period “village.”

▶ Large Raised-Floor Building Remains
These are the remains of buildings constructed by digging holes in the ground and setting pillars upright. The postholes were about 2 meters in diameter, about 2 meters deep, and spaced 4.2 meters apart, with chestnut pillars about 1 meter in diameter inside. Because of abundant groundwater and the charring of the areas around and beneath the wooden pillars, they did not decay and have survived. They are thought to have been large elevated buildings with six pillars and a rectangular plan.

▶ Earthen Mound
When soil was dug out for pit dwellings and large postholes, the excavated earth, ash, burned soil, everyday refuse such as pottery and stone tools, and other waste were discarded repeatedly. As a result, the area became higher than the surroundings and eventually formed a mound-like hill. Because the soil accumulated in horizontal layers, it is thought to have been leveled. A large number of pottery and stone tools were found here, along with many ritual-related artifacts such as clay figurines, jade, and small pottery vessels.

▶ Valley
The valley was used as a dumping ground. Because it was moist and cut off from the air, not only pottery and stone tools but also wooden products, lacquerware, animal and fish bones, scales, plant seeds, nuts, and parasite eggs, which do not usually survive, were preserved in excellent condition.

▶ Pit Dwellings
Jomon-period dwellings were built by digging into the ground to create the floor, with a hearth in the center. The layout of the dwelling, the arrangement of pillars, and the position and structure of the hearth vary according to the period.

▶ Large Pit Dwelling Remains
Dwellings longer than 10 meters are called large dwelling remains. At the Sannai-Maruyama Site, the largest discovered measures about 32 meters in length and about 10 meters in width. They are often found near the center of the settlement, and theories suggest they may have served as meeting halls, communal workspaces, or communal housing.

▶ Raised-Floor Building Remains
These are thought to have been supported by pillars set in postholes dug into the ground. They were found in dense clusters in the center of the settlement and to the west of the southern mound.

▶ Buried Pottery
When children died, they were placed inside pottery vessels with round holes made in them or with the rim or bottom broken off, and buried near dwellings. In many cases, fist-sized round stones were found inside the vessels, which are thought to be related to customs of the time.

▶ Pit Graves
Adults were buried in circular or oval pits dug into the ground. The graves were arranged in two rows on both sides along a road on the eastern side of the settlement.

▶ Road Remains
The road extends from the center of the settlement toward the sea, spanning about 12 meters in width and 420 meters in length. Some sections were slightly dug down into the ground, forming shallow ditches, while others were “paved” by adding more soil. Recent surveys have also discovered a north-south road.

▶ Clay Quarry Pits
These are pits dug to extract clay for making pottery. It seems that pottery was made using fine-grained volcanic ash with properties similar to clay.

▶ Storage Pits
These were built in groups near the outer edge of the plateau. Many have a bottle-like cross-section with a narrow opening and wide bottom, and are thought to have been used to store food such as chestnuts and other nuts. Some are large, with a depth of nearly 2 meters.