The Sannai Maruyama Site
Today, when we Japanese hear the word “the Jomon Period,” some people still picture a bearded half-naked man holding a spear. Well, that kind of image may not be completely wrong (because the Jomon people were still basically hunter-gatherers, anyway), but such a primitive lifestyle might have become slightly obsolete by the middle of the Jomon Period. After several excavations conducted throughout the country in the 1990s, a lot of new facts were revealed about the lives of the Jomon people which have greatly changed our conventional views about them.
Until the late 20th century, the Jomon people were believed to have relied completely on hunting and gathering. But studies revealed that the plant cultivation was already being done in some regions by the middle of the Jomon Period. For example, there are some pieces of evidence suggesting that Jomon people cultivated soybeans in several places in the Kyushu Region as well as in the main island of Honshu.
Above all, the excavation of the Sannai Maruyama Site in Aomori Prefecture in the Tohoku Region and what was subsequently revealed by extensive research surprised most people a lot. The existence of this site was already known in the Edo Period (1603 – 1867) because fragments of pottery or clay figurines called dogu (土偶) were sometimes unearthed even at that time. But in 1994, during a survey which was started two years earlier for the purpose of building a prefectural baseball stadium, researchers found six large pieces of chestnut tree trunks. And that led them to think that these had been the pillars of something large and the site used to be a large ancient settlement. Realizing the significance of this discovery, the prefectural government then decided to halt the stadium construction and embarked on research and a full-scale excavation.
Today, it is known that the Sannai Maruyama was a flourishing Jomon village which lasted for as long as some 1,500 years, from about 5,500 to 4,000 years ago. Many findings tell us that the villagers were intelligent people whose compassion was evident by the way they cherished the memory of their ancestors. The graves were neatly arranged on both sides of the streets and children were also carefully buried in earthenware.
What surprised people the most was how big some of the buildings were and how well organized the entire village was. They found about a dozen traces of huge pit dwelling houses, and the largest of them spanned about 32 meters in length and 9.8 meters in width. With a total floor space of 250 square meters, this one is considered to be the largest pit house in Japan. Now, there is a reconstructed version of this structure in the compound and we can actually enter into it to see its interior. It is not clear what purposes this structure was used for, but researchers think it was some kind of communal hall or a workshop for the village residents.
Another important reconstruction in the compound is the large “six-pillar structure,” which is one of the highlights for visitors to the Sannai Maruyama Site. First, they discovered the six holes (which I mentioned above), each with a diameter and depth of about two meters. These holes were neatly arranged in two rows 4.2 meters apart. And in each hole there remained the remnant of a chestnut tree trunk, which led them to conclude that this was a large building supported by six huge pillars made out of chestnut tree trunks. Again, it is not known why this structure was built, but some speculate that it was a watch tower, while others think it was used for some religious purposes.
Other than the huge buildings mentioned above, there were a considerable number of smaller structures. While most of them were obviously typical pit-dwelling houses, several of them are thought to have been pillar-supported buildings with a raised-floor because researchers couldn’t find any signs of flooring or hearth on the ground. As with the large “six-pillar structure,” the pillars of these buildings were arranged with an equal space. (Multiples of 35 centimeters were often used in the Jomon Period to measure the space between the pillars.)
The total area of Sannai Maruyama Site spans about 35 hectares, which is seven times larger than the area of the Tokyo Dome baseball stadium. This site had a large garbage dump in the area which is now called the Northern Valley, as well as a huge “earth mound” called morido at the south, north, and west sides of the compound. These mounds were formed mainly by piling up earth displaced when the hearth for pit-dwellings were dug. The heights of these mounds are, in some parts, taller than an average human.
Huge amounts of artifacts have been unearthed from the garbage dump and mounds. It is said that the total amount of pottery fragments excavated at the Sannai Maruyama Site was so large that tens of thousands of crates were required to store them. Also, more than 1,500 pieces of dogu figurine have been discovered, most of them from the northern and southern mounds. Some researchers assume that these figurines were generally used for some kind of religious or shamanistic purposes on occasions such as festivals. Other findings include various types of ornaments and tools made of jade or obsidian. Since these materials were not indigenous to the region, it is obvious that trade had already been conducted actively between several places across the country.
In addition to these “visible” findings, there are a couple of facts which were revealed through extensive scientific research. For example, they analyzed the DNA of the chestnuts excavated at the Sannai Maruyama Site, and concluded that those chestnut trees were not the wild species but the cultivated ones. Studies of pollen traces in the soil also suggested that, in the middle of the Jomon Period, there were chestnut tree forests close to the settlement. Being resistant to moisture, chestnut lumber is an ideal material for home construction. It is assumed that people at Sannai Maruyama cultivated chestnut trees not only to eat their nuts, but also to use them as a building material when there was a need.
All of these findings from the Sannai Maruyama Site surprised us a lot in the 1990s because they presented to us a much more cultured, intelligent, and organized image of Jomon people than we had imagined them to be.
Today, it is believed that the Sannai Maruyama Site was not an isolated settlement in that remote area of Aomori Prefecture, but was part of much larger settlement that spread over the surrounding prefectures including Hokkaido. They are collectively called the “Archaeological Sites in Hokkaido and Northern Tohoku.” And there has been an active campaign by people in Hokkaido and the prefectures of Aomori, Akita, and Iwate, aiming for its entry into the UNESCO World Heritage list.
The technique of rice cultivation in the paddy field was introduced to Northern Kyushu through the Korean Peninsula around 900 BCE (although there are still some controversies over the exact date of this), and eventually spread to the main island of Honshu. And it is generally understood that it was around this point that the Jomon Period finally ended and a new era, the Yayoi Period, began in Japan.
Photographs: taken at the Sannai Maruyama Site, by T. Terada.