Moriyama Ruins

Moriyama Archaeological Site: A Window into Jomon Life in Southern Kyoto

Perched atop a terrace overlooking the Kizu River in Joyo City, Kyoto Prefecture, the Moriyama Archaeological Site (森山遺跡) offers a rare and fascinating glimpse into the daily lives of Japan's ancient inhabitants. Designated as a National Historic Site in 1978, this remarkable settlement spans an extraordinary timeline—from the Late Jomon period (approximately 4,000 years ago) through the Yayoi and Kofun periods—making it one of the most significant multi-period archaeological sites in the Kinki (Kansai) region.

Today, the site has been carefully preserved as a public history park, where visitors can walk among partially restored pit-dwelling foundations and imagine the vibrant community that once thrived here. For travelers seeking an authentic encounter with Japan's deep prehistory beyond the famous temples and shrines, Moriyama offers a uniquely rewarding experience.

Historical Background and Significance

The Moriyama Archaeological Site sits on an elevated plateau at approximately 35 to 38 meters above sea level, along the western edge of Joyo City where the Kizu River flows north to south. The site was first excavated in 1975 and 1976 by the Joyo City Board of Education during preparations for residential development. The extraordinary findings led to its designation as a National Historic Site (国指定史跡) on February 8, 1978.

The primary importance of Moriyama lies in its status as a core Jomon-period settlement in the Kinki region. Jomon settlements are relatively rare in western Japan compared to the Kanto and Tohoku regions, making Moriyama an invaluable site for understanding how Jomon people lived in this part of the Japanese archipelago. The site has yielded an exceptionally rich collection of artifacts, demonstrating that it served as a central hub for the surrounding communities during the Late Jomon period.

Jomon Period Settlement (c. 2000 BCE)

The heart of the Moriyama site is its Late Jomon period settlement, dating to approximately 4,000 years ago. Archaeologists discovered six pit dwellings (竪穴住居), the largest of which measures an impressive 10 meters in diameter—a circular structure that would have housed an extended family or served a communal purpose. The remaining dwellings range from 6 to 10 meters across, and the variation in size is thought to reflect differences in the number of occupants.

Each dwelling features a sunken earth hearth (地床炉) at its center, slightly hollowed into the floor for cooking and warmth. Around the dwelling area, numerous pits of various sizes have been found, though their exact purposes remain a subject of scholarly discussion. The southwestern portion of the settlement was notably free of such pits, suggesting it may have functioned as a communal gathering space or village plaza.

Along the southern edge of the settlement, archaeologists uncovered a stone arrangement (配石遺構) composed of fist-sized river cobbles, which may represent a burial site. This finding adds another dimension to our understanding of the spiritual and ritual practices of the Moriyama community.

Yayoi and Kofun Period Remains

Although the Jomon layers are the site's primary claim to significance, Moriyama also preserves evidence of continued habitation during subsequent periods. From the Yayoi period, two additional pit dwellings and one jar burial (甕棺) have been identified, showing that the favorable hilltop location continued to attract settlers even as Japanese society underwent profound changes with the introduction of rice cultivation.

The Kofun period (roughly 3rd to 7th century CE) left an even more substantial footprint, with 12 pit dwellings and a particularly intriguing rectangular moated enclosure. This structure—measuring approximately 40 meters east to west and 32 meters north to south—was created by building up an earthen platform surrounded by a moat 4 meters wide and 1.5 meters deep. Small post holes along the platform edges and moat floor suggest some form of palisade or fence once stood here.

In the southwestern corner of the moat, a concentration of early Haji ware (土師器) pottery, including high-footed cups (高坏) and small round-bottomed vessels, was discovered. Some researchers interpret this assemblage as evidence of funeral rites or other ceremonial activities, possibly indicating that the enclosure served as the residence of a local elite figure during the early Kofun period.

Why Moriyama Was Designated a National Historic Site

The designation of Moriyama as a National Historic Site reflects several factors that make it exceptionally valuable to Japanese archaeology. First, Jomon-period settlements in the Kinki region are exceedingly rare. While the Jomon culture flourished for thousands of years across Japan, well-preserved village sites in western Japan are few and far between. Moriyama stands out as the largest known Jomon settlement in southern Kyoto Prefecture.

Second, the sheer abundance and variety of artifacts recovered from the site demonstrate that Moriyama was not a minor outpost but a thriving central settlement. The extensive evidence of stone tool production, the diverse pottery styles, and the large-scale dwellings all point to a community of considerable size and sophistication.

Third, the multi-period nature of the site—with occupation layers spanning from the Jomon through the Kofun period—provides an unusually comprehensive record of how human communities in this part of Japan evolved over approximately 2,500 years. This continuity of habitation makes Moriyama an invaluable resource for understanding the long arc of Japanese prehistory in the Kinki region.

Highlights and What to See

The Moriyama Archaeological Site has been developed as a history park (史跡公園), offering visitors an open-air experience of Japan's ancient past. The park features partial reconstructions of the Jomon-period pit dwelling foundations, allowing visitors to appreciate the scale and layout of the original settlement. Wooden frameworks mark the outlines of the circular dwellings, giving a tangible sense of how these structures once appeared.

The site is set in a quiet, elevated location surrounded by residential areas, providing a peaceful atmosphere for contemplation. Information panels (primarily in Japanese) explain the site's history and the significance of the various features. The hilltop setting itself is part of the experience, as visitors can appreciate why ancient people chose this spot—commanding views of the surrounding landscape and the Kizu River valley below.

For those who wish to see the actual artifacts recovered from Moriyama, a visit to the nearby Joyo City Historical Folk Museum (城陽市歴史民俗資料館), affectionately known as the "Gori-Gori-Kan" (五里ごり館), is highly recommended. The museum's permanent exhibition traces the history of Joyo from the Paleolithic era to the modern day, featuring archaeological finds from across the city including items from the Moriyama site.

Nearby Attractions

Joyo City is remarkably rich in archaeological heritage, making it possible to combine a visit to Moriyama with several other fascinating historic sites nearby.

The Kuzetsuka Kofun Group (久津川古墳群), designated as a National Historic Site, includes the largest ancient burial mound in the southern Yamashiro region. The Shibagahara Kofun (芝ヶ原古墳) is another must-see, with its excavated artifacts—including a rare bronze bracelet and a four-beast mirror—designated as Important Cultural Properties and displayed at the Gori-Gori-Kan museum.

The Shoan-ji Temple Archaeological Site (正道官衙遺跡), believed to be the remains of the ancient Kuse District government office from the Nara period, has also been preserved as a history park. The Kyoto Prefectural Kizugawa Sports Park (城陽五里五里の丘) is located just 500 meters from Moriyama and offers a lovely natural setting for families. Along the Kizu River, the Yamashiro Old Road (山背古道) walking trail connects various historical sites across the region and provides a wonderful way to explore the area on foot.

Practical Information for Visitors

The Moriyama Archaeological Site is an open-air park with free admission and no set opening hours, making it accessible at any time. The site is located in a residential neighborhood, so visitors should be considerate of local residents. Signage within the site is primarily in Japanese, so international visitors may wish to research the site in advance or bring a translation app.

Spring is a particularly lovely time to visit, when cherry blossoms frame the ancient ruins. Autumn brings pleasant temperatures and beautiful foliage. Summer can be quite hot and humid in the Kyoto basin, so early morning visits are advisable. The nearby Gori-Gori-Kan museum is an excellent indoor complement, especially on rainy days.