Seta Hills Production Sites

The Seta Hills Production Sites are a group of ancient industrial facilities identified as archaeological sites. The sites are found in the Seta Hills, extending from southeast Lake Biwa to Kusatsu and nearby areas. The ruins were built due to local iron ore deposits and the abundance of forest resources that provided charcoal for iron-making during the Nara period, with the sites being most active during the time the capital was at the Ōmi Ōtsu Palace (667-672 AD). In 1985, the Seta Hills Production Sites were collectively designated a National Historic Site of Japan.