Kitakogane Site
The Kitakogane Site in Date, Hokkaido, dates from 5000 to 3500 BCE. Archaeologists have uncovered large shell mounds, several sets of human remains, and a range of artifacts that provide evidence of complex ritual practices. The site is on a hillside facing Uchiura Bay, a few hundred meters from the shore. At the entrance to the site, there is a museum with exhibits and multilingual information.
Findings from the shell mounds
Five shell mounds have been discovered at the Kitakogane Site. They contain the shells of saltwater clams, oysters, and sea urchin, as well as the bones of fish, fur seals, whales, deer, and other animals. Discoveries of burial pits within and beneath the shell mounds suggest they were places of ritual significance. One of the mounds has yielded 14 sets of ceremoniously buried human remains and decorative spoons carved from whale bone and deer antler. In another mound, the skulls of deer were found arranged in an intentional pattern.
Shell mounds and the shoreline
Shell mounds were made close to the shore, so as the shoreline receded over time, the location of the shell mounds moved down the hillside. The oldest shell mound is the highest, while the others are located successively lower. Over the course of approximately 1,500 years, the climate cooled and the sea level fell, causing the shoreline to recede.
Diet and livelihood
Studies of the human remains suggest that the inhabitants of the Kitakogane Site consumed more fish than meat, and nuts in relatively modest quantities. The bones contain high levels of protein derived from fish and other marine life. Cavities are a sign of heavy nut consumption, but the teeth found at the site have no cavities.
It is likely that fishing was the main subsistence activity. Tools such as net sinkers made from stone and fishhooks and harpoon heads made from antler have been found across the site.
Ritual deposits of stone tools
Vast quantities of stone tools have been discovered near a spring at the foot of the hillside. The area has been left as it was excavated, with stone tools such as grinding stones and milling basins clearly visible, embedded in the earth. Many of the items appear to have been intentionally broken or deliberately scraped and damaged. Archaeologists believe the items were discarded here in a ritual manner that had symbolic meaning to the inhabitants of the site. It is not known why the tools were discarded in this way, but some archaeologists surmise that it may have been an expression of gratitude, possibly to the tools themselves, or to the water which supported life at the settlement.
Kitakogane Site Information Center
The Kitakogane Site Information Center exhibits artifacts from the site and displays an actual cross section from one of the shell mounds. Signs in English and Japanese indicate the types of bones and shells visible in the cross section. Artifacts displayed at the center include decorative items carved from antler and bone, hunting tools such as stone arrowheads and harpoon heads made from antler, as well as grinding stones including saddle quern milling stones. The grinding stones are displayed in a hands-on area and can be picked up and examined freely. The museum is free of charge.
Related archaeological sites
The Irie Site [link] and the Takasago Burial Site [link] are 30 minutes from the Kitakogane Site by car. Shell mounds have been found at both of these sites. The Ofune Site [link] and the Kakinoshima Site [link] are large sites on the opposite side of Uchiura Bay. The Hakodate Jomon Culture Center [link] displays artifacts from these two sites and gives a comprehensive overview of prehistoric life in northern Japan.