Shibagahara Tomb

Shibagahara Kofun: A Journey to the Dawn of Japan's Burial Mound Era

Tucked away on a quiet hilltop in the city of Joyo, just south of Kyoto, the Shibagahara Kofun (芝ヶ原古墳) is one of Japan's oldest known burial mounds. Dating back to the early 3rd century — the time of the legendary Queen Himiko — this ancient tomb offers a rare window into the very beginning of the Kofun period, when powerful chieftains first began constructing monumental graves across the Japanese archipelago. Designated as a National Historic Site and home to artifacts classified as Important Cultural Properties of Japan, the Shibagahara Kofun is a must-visit destination for archaeology enthusiasts and travelers seeking to experience a side of Japan's history that few foreign visitors ever discover.

What Is the Shibagahara Kofun?

The Shibagahara Kofun, also known as Shibagahara Tomb No. 12, is a zenpō-kōhō-fun (前方後方墳) — a distinctive keyhole-shaped burial mound formed by two adjoining rectangular sections. The posterior (rear) square portion measures 21 meters from north to south and 19 meters from east to west, while the anterior (front) section, partially lost to road construction, originally extended at least 3.5 meters with a connecting neck of 11.6 meters wide. Unlike later, more elaborate kofun, the mound features no stone facing (fukiishi) and no terraced construction, reflecting the simple yet significant early style of burial mound architecture.

The tomb is part of the larger Shibagahara Kofun Cluster, itself a sub-group of the renowned Kutsukawa Kofun Cluster, which encompasses nearly 100 burial mounds scattered across the northern hills of Joyo City. The Shibagahara cluster alone contains 13 tombs spanning from the 3rd to 7th centuries.

Why Was It Designated a National Historic Site?

Discovered during a rescue excavation in the summer of 1986, ahead of planned residential development, the Shibagahara Kofun immediately drew national attention. The tomb is estimated to have been constructed in the early to mid-3rd century, making it one of the earliest kofun in all of Japan. In the southern Yamashiro region, it predates even the famous Tsubai Otsukayama Kofun, positioning its occupant as one of the most powerful local chieftains of the era.

The site was officially designated a National Historic Site in 1989, with an expansion of the protected area added in 2012. Separately, the collection of artifacts excavated from the tomb was designated as a National Important Cultural Property in 1990, in recognition of their exceptional archaeological significance.

Remarkable Artifacts: The Treasures Within

The burial pit at Shibagahara contained a directly interred combination wooden coffin measuring 3 meters long and 0.8 meters wide, set within a larger pit of 4.7 by 2.5 meters. Found near the northern end of the coffin, the grave goods tell a compelling story of wealth and authority in ancient Japan:

• Dōkushiro (Bronze Bracelets): Two identical bronze arm rings, modeled after shell bracelets from the Amami Islands in southern Japan. These are the only complete examples of their kind ever found in the country, making them uniquely valuable.
• Shijūkei-kyō (Four-Beast Mirror): A Japanese-made imitation of Chinese bronze mirrors, measuring 12 cm in diameter and featuring stylized animal motifs.
• Jadeite Magatama: Eight curved jade beads, symbols of prestige and spiritual power.
• Jasper Tubular Beads: An astonishing 187 finely crafted green jasper beads.
• Glass Beads: A total of 1,276 tiny glass beads, suggesting extensive trade connections.
• Iron Tools: Including a yariganna (iron plane), iron needles, and an iron arrowhead fragment.

On the gravel surface above the burial pit, Shonai-style pottery — including four double-rimmed jars and one tall-footed cup — was placed as ritual offerings. This pottery style is characteristic of the transitional period between the Yayoi and Kofun eras, further confirming the tomb's extraordinary antiquity.

Highlights and What to See

Today, the Shibagahara Kofun has been beautifully restored and opened to the public as a historic park. The mound itself has been reconstructed to approximate its original appearance, allowing visitors to walk around and atop the ancient tomb. From the summit, you can enjoy a panoramic view to the north, where the massive Kutsukawa Kurumazuka Kofun — the largest keyhole-shaped tomb in the Yamashiro region — is visible as a forested mound in the distance.

The park features an experience plaza with a ceramic topographic model showing the distribution of ancient tombs and temple ruins in the area. A rest house equipped with explanation panels and replicas of the bronze bracelets and mirror allows visitors to actually touch reproductions of these ancient treasures. Public restrooms are also available, making the site a convenient base for exploring the wider kofun landscape of Joyo City.

Joyo City History and Folklore Museum (Gori-Gori-Kan)

To see the actual excavated artifacts — designated as Important Cultural Properties — visitors should head to the Joyo City History and Folklore Museum, affectionately nicknamed "Gori-Gori-Kan" (五里ごり館). The museum's name comes from Joyo's historic position exactly five ri (about 20 km) from both Kyoto and Nara. The permanent exhibition traces local history from the Paleolithic era to modern times, with highlights including a full-scale replica of the stone coffin from Kutsukawa Kurumazuka Kofun and, of course, the remarkable bronze bracelets and mirror from the Shibagahara Kofun.

The museum is located on the 4th floor of the Bunka Parc Joyo complex, which also houses a planetarium, a library, and event halls. Admission is 200 yen for adults and 100 yen for children. It is open from 10:00 AM to 5:00 PM (last entry at 4:30 PM) and is closed on Mondays and during the New Year holiday period.

Surrounding Area and Nearby Attractions

Joyo City is often called the "City of Kofun," with approximately 150 confirmed burial mounds within its borders. Several other notable sites are within easy walking or cycling distance of the Shibagahara Kofun:

• Kutsukawa Kurumazuka Kofun: The largest keyhole-shaped tomb in the Yamashiro region, with an overall length of 161 meters including its surrounding moat. Built in the mid-5th century, it represents the peak of local power.
• Basho-zuka Kofun: A 5th-century circular tomb with a diameter of 27.5 meters, notable for its haniwa clay figures and pottery from the Korean Peninsula.
• Shibagahara Kofun Park (Wider Cluster): The surrounding 13-tomb cluster includes keyhole-shaped, circular, and square tumuli spanning several centuries.

Beyond the ancient sites, the nearby city of Uji — famous for its matcha green tea and the stunning UNESCO World Heritage Site of Byodo-in Temple — is just a short train ride away. The Kyoto Prefecture Yamashiro Folk Museum in Kizugawa City also displays replica artifacts from the Shibagahara Kofun.

How to Get There

The Shibagahara Kofun is accessible by both JR and Kintetsu railway lines. From JR Joyo Station on the JR Nara Line, it is approximately a 15-minute walk. Alternatively, from Kintetsu Kutsukawa Station, walk east for about 10 minutes (approximately 800 meters). The park is open from 9:00 AM to 5:00 PM (until 4:30 PM from November through January), and admission to the outdoor park is free. The park is closed from December 29 to January 3.