This remains were discovered by students of Metropolitan Oshima High School, and others.
Layers including materials were identified at 3 sites of A, B and C, through investigations conducted for 3 years starting from 1982 by Boards of Education of Tokyo Metropolitan Government and of Oshima Town. At Site A on water's edge in particular, pit dwellings and earthen pits were identified as being attributable to the Initial Jomon Period, and abundant potteries, stone tools and animal bones were excavated. Among obsidian pieces used for stone tools, the ones from Kozu Island were also found, which suggests exchanges between islands like Oshima. The remains now attract attention as the oldest ones among the ones discovered in Izu Islands. At Site C on the middle of the cliff, the relics were excavated from the Middle to the Late Jomon Period, while at Site B on the cliff – from the Nara to the Heian Period.
The remains reveal that the island has been inhabited for at least 8,000 years.