Yubama Ruins

The Oldest Traces of Humans on Hachijojima

The First Jomon People Who Came by Dugout Canoe

This is the oldest ruin on Hachijojima, located on a scenic hill overlooking Aogashima, dating from the end of the Initial Jomon period (about 7,000 years ago) to the beginning of the Early Jomon period (about 6,500 years ago). The Yubama people are thought to have come to Hachijojima in groups, island-hopping in dugout canoes. It is assumed that they did not live there continuously, but for a short period of time, though it is not known whether they moved to another island or were wiped out by a disaster such as an eruption or tsunami.

The Discovery of the Yubama Ruins, which Overturned Conventional Wisdom

In 1962, a local junior high school student discovered a large polished stone ax at the construction site of a greenhouse at the Hachijo Onsen Hotel. The following year, the Tokyo Metropolitan Government inspected the site and confirmed several stone tools. In 1964, the first excavation on Hachijojima was conducted by the Archaeology Laboratory of Meiji University, overturning the previous view that "there were no Stone Age inhabitants on Hachijojima beyond the Kuroshio Current," and revealing that people had lived on Hachijojima since the Jomon period.

Pit Dwelling Sites

Surveys to date have confirmed depressions that are thought to be the sites of about three dwellings, but because the excavation area was limited, it is possible that the ruins covered a much wider area.

Artifacts Different from Mainland Jomon Culture

The pottery from the Yubama Ruins is characterized by being "thick and unpatterned." It is unique, with no parallels in Jomon pottery from other Izu Islands or the mainland, and the stone tools are also significantly different from those of the Early Jomon period on the mainland. One reason for this is thought to be that the pottery was made on the island, and the lack of suitable materials (clay and sand) for making pottery resulted in it being thick and unpatterned.