SHIGA, Nov 25, 2025 (News On Japan) - Jomon pottery estimated to be more than 10,000 years old has been found almost perfectly preserved at the bottom of Lake Biwa, with researchers calling the discovery exceptionally rare.
The pottery was uncovered at the Tsuzuraozaki Underwater Site, located about 700 meters offshore from the lakeside in Nagahama City, Shiga Prefecture, at a depth of around 70 meters. The site has yielded multiple pottery fragments in the past, but the newly discovered piece identified during an unmanned submersible survey conducted by the prefecture in October is believed to date from roughly 10,500 to 11,000 years ago and remains almost entirely intact, a condition described as highly unusual.
Pottery excavated on land is typically found in damaged or fragmented form, yet researchers say that because this vessel remained submerged, it appears to have been preserved in the state it was in at the time it sank.
Shiga Governor Daizo Mikazuki said the underwater environment may offer research benefits, adding that "because it was preserved at the bottom of the lake, there may be discoveries here that cannot be found elsewhere."
The prefecture is continuing its investigation, considering the possibility that cargo from boats used during the period may also have fallen and settled around the site.
Source: YOMIURI
