Jōmon

Twenty minutes from your berth, a hillside holds the remains of a settlement occupied continuously from roughly 3900 to 2200 BCE. Seventeen hundred years — longer than the span between the Roman Empire and now. Several hundred buildings, most of them pit dwellings, have been identified across some forty hectares, along with burial pits and large numbers of clay figurines.

And the people who lived here were hunter-gatherers.

Why archaeologists care so much

The story Western education tells about civilisation runs: farming, then surplus, then settlement, then everything else. The Jōmon refused that order. UNESCO inscribed seventeen sites across four prefectures in 2021 precisely because they evidence people who "led sedentary lifeways based on hunting, fishing and gathering" — permanence without agriculture, sustained for over ten thousand years.

Sannai-Maruyama makes the case physically. There is jade here from Niigata and obsidian from Hokkaido, materials that travelled up to five hundred kilometres. There is lacquerware, amber, basketry. And there are chestnuts — DNA testing showed the chestnuts were cultivated, a managed grove. These were hunter-gatherers who were also orchardists, and who then built with the same tree they ate from.

The six holes

The site's signature is a structure raised around 2600 BCE: six chestnut pillars, each about a metre thick, set in two rows of three, spaced exactly 4.2 metres apart, in post holes uniformly two metres deep and two metres wide. The bases were deliberately scorched to resist rot.

What stood on them is genuinely unknown. The reconstruction you will see rises about twenty metres, and that height — along with the building's purpose — is inference, not excavation. Only the holes and the charred stumps survive. English pages tend to assert the tower as fact; the honest version is better anyway. Six holes, a repeated unit of measure, and thirty years of argument about what it held up.

Whatever it was, they measured it. That is the astonishing part — not the height, but the 4.2 metres, repeated exactly.

Saved by cancelling a baseball stadium

Travellers had been picking pottery off this hillside since the Edo period, and surveys ran on and off from the 1950s. Then in 1992 the prefecture began building a baseball stadium here. Rescue excavation in June 1994 uncovered the six-pillar foundations. That August, the prefecture cancelled the stadium.

It became a National Historic Site in 1997, a Special Historic Site in 2000, and part of a World Heritage listing in 2021. Japan's greatest prehistoric town survives because someone chose a 5,900-year-old village over a ballpark.

One correction worth making

You will read that Jōmon pottery is the oldest in the world. It is not, quite. Sherds from the Ōdai Yamamoto I site — also in Aomori Prefecture, also part of the World Heritage listing — date to roughly 16,500 years ago, which makes them the oldest pottery in Japan and among the oldest on Earth. Pottery from Hunan, in China, is around a thousand years older. The Aomori sherds are also, charmingly, undecorated — no cord marks at all, despite jōmon meaning "cord-marked."

Visiting from a cruise call

Sannai-Maruyama is about 30–40 minutes by city bus from Aomori Station (¥310), or by the Nebutan-go from the station's West Exit (¥300, four a day). Admission is ¥500 and the free English audio guide is genuinely good. Allow ninety minutes to two hours for the site and its museum wing. The Aomori Museum of Art — with the giant white Aomori-ken dog — is a ten-minute walk away, so one taxi fare covers both.

For a port day, the arithmetic works comfortably on four hours or more; on a short call the waterfront is the better use of your time.