The Ikegami-Sone Site is a large archaeological site from the middle Yayoi Period, located across Ikegami-cho in Izumi City and Sone-cho in Izumiotsu City, Osaka Prefecture. It is the remains of a moated settlement that flourished during the Yayoi Period.
The site extends approximately 1.5 km from north to south and 0.6 km from east to west, covering a total area of about 600,000 square meters. It was designated a National Historic Site in 1976, and preservation and development work has been carried out since 1995.
The discovery of the Ikegami-Sone Site dates back to around 1900, although it attracted little attention at first.
Excavations conducted between 1969 and 1971 in connection with road construction revealed that the site was a large settlement extending over more than 20,000 square meters. However, archaeological attention later shifted to other sites, and research temporarily slowed.
Investigations resumed in the 1990s, when large post-built structures were discovered. These findings brought renewed attention to the importance of the site.
At the center of the Ikegami-Sone Site is a large post-built structure with ridge-supporting pillars. These buildings were constructed around a well and are thought to have served important roles within the settlement, possibly as a ritual space or residence of a local leader.
The buildings were repeatedly rebuilt over a period of nearly 100 years during the middle Yayoi Period, indicating that this was an important and long-lasting center of the settlement.
The settlement was surrounded by moats that were dug and expanded several times during the middle Yayoi Period. At some point, however, construction of the moats stopped.
Although groups of post-built structures continued to be constructed afterward, the settlement gradually became smaller. It is thought that the community eventually moved its main base elsewhere.
One theory suggests that the settlement’s center may have shifted to the Kannonchiyama Site in the hills behind the Ikegami-Sone Site.
Large numbers of stone sickles made from green schist have been excavated at the Ikegami-Sone Site. The stone was obtained from the Kino River basin in Wakayama Prefecture, suggesting that the site may have functioned as a distribution center for stone sickles.
Numerous stone weapons made from sanukite from Mount Nijo have also been discovered. These finds provide evidence of a production and distribution network centered on stone tools in the Kinki region during the Yayoi Period.
Another distinctive discovery is a long-necked jar decorated with a dragon, believed to date from the late Yayoi Period. It is thought to have been associated with rituals related to water.
In ancient China, dragons were regarded as divine beings associated with rainmaking. The discovery suggests that knowledge and beliefs concerning dragons and rain may have reached the Kinki region.
Archaeological investigations at the Ikegami-Sone Site have been conducted intermittently since the beginning of the 20th century.
Following the major excavations from 1969 to 1971, surveys continued and expanded in 1974, 1978, 1987, 1990, and other years. These investigations gradually revealed the extent of the settlement and led to the discovery of many artifacts and structural remains.
Excavations have uncovered a variety of remains dating mainly from the middle Yayoi Period, including wells, square-moated burial mounds, post-built structures, and pit dwellings.
One of the most remarkable discoveries is a huge well measuring approximately 2 meters in diameter and 1.2 meters deep. Its wooden lining was made from a single camphor tree estimated to have been around 700 years old.
The site also contains square-moated burial mounds, raised-floor buildings, and pit dwellings dating from the middle Yayoi Period.
The spacing and scale of the pillars of the raised-floor buildings indicate that some of these structures were likely important facilities within the settlement.
Today, the Ikegami-Sone Site has been developed as a historic site park. Facilities include the Ikegami-Sone Yayoi Information Center and the Ikegami-Sone Yayoi Learning Center.
These facilities provide information about the archaeological site and Yayoi-period culture, while also offering opportunities for hands-on educational activities.
The information center provides information about the archaeological site and guidance for visitors to the historic park.
The learning center offers hands-on activities through which visitors can learn about everyday life during the Yayoi Period.
The Ikegami-Sone Site is approximately a 7-minute walk from Shinodayama Station on the JR Hanwa Line.
It is also approximately an 18-minute walk from Matsunohama Station on the Nankai Main Line.
The Ikegami-Sone Site is an important archaeological site for understanding the Yayoi Period in the Kinki region. Today, it is also enjoyed as a historic site park where visitors can explore the remains of an ancient settlement.
The structures and artifacts discovered here offer valuable insights into the daily life, technology, trade, and religious beliefs of people living in ancient Japan. A visit provides an opportunity to explore a fascinating chapter of Japanese history while walking through the landscape where a Yayoi-period community once lived.