Giant Yayoi Building at Omi Site Reveals Ancient Distribution Networks
Archaeological findings released on August 6, 2026, detail a large building at the Nakahata-Furisato site in Yasu, Shiga Prefecture, dating to the late middle Yayoi period around the turn of the Common Era. The structure stood at the core of a new distribution network centred on the Konan area of the Omi region, whose distinctive pottery spread across the Kinki region, the Sea of Japan coast, and the Ise Bay shore from the first century BCE. The findings link the network to metalworking with continental imports and the later construction of the Ise site, underscoring Lake Biwa's roughly 2,000-year role as a goods distribution hub.
Archaeological findings released on August 6, 2026, describe a large building discovered at the Nakahata-Furisato site in Yasu, Shiga Prefecture, dating to the late middle Yayoi period, around the turn of the Common Era. During this period, numerous key settlements in the Kinki region were coming to an end, leaving society in a state of upheaval. Research on Yayoi pottery from the Omi region shows that wares from the Konan area of the Yasu River basin spread to various regions at the same time, indicating the formation of new distribution networks. The giant building stood at the core of this network, though its specific function remains to be clarified.
During the middle Yayoi period, jar-shaped pottery used in the Omi region developed distinctive regional characteristics, with rims rising vertically, known as "ukeguchi-shaped rim jars." These vessels were produced in the Konan region and spread from the first century BCE to the Kinki region, the Sea of Japan coast, and the Ise Bay shore. The jars were everyday cooking vessels, and their distribution patterns are linked to the movements of local populations, though the precise correspondence remains unclear.
The middle Yayoi period in the Kinki region saw the rise of moated settlements such as Ikegami-Sone and Karako-Kagi, but most were dissolved in the late middle period. Around the same time, the Konan region began producing metal goods from iron and copper imported from the continent, and the base for manufacturing bronze bells, or dotaku, also moved from central Kinki to this area. These changes accompanied the development of the distribution networks.
More than half a century after the construction of the large building at Nakahata-Furisato, the Ise site began to be developed. Excavations there revealed orderly square divisions and more than ten large buildings arranged in a ring. The findings indicate that religious and political alliances had formed in the Omi region, along with inter-regional distribution networks. These networks are regarded as the foundation of state formation, with influence extending to later periods. Lake Biwa's history as a hub for the collection and distribution of goods dates back roughly 2,000 years, as evidenced by the distribution patterns of the ukeguchi-shaped rim jars.