Bone Repository Vessel from Miyajidake Shrine: A National Treasure of Ancient Funerary Art

Hidden within the verdant hillside of Miyajidake Shrine in what was once Chikuzen Province (present-day Fukutsu City, Fukuoka Prefecture), a remarkable archaeological discovery was made in 1938. During routine tree-planting work on the eastern slope near the famous Miyajidake Kofun, workers unearthed a set of nested containers just beneath the surface—a bone repository vessel, or kotsuzōki, dating to the Nara period (8th century). This extraordinary artifact, now designated as a National Treasure of Japan, offers a fascinating window into the funerary practices and artistic craftsmanship of ancient Japan.

Today, the bone repository vessel is housed at the Tokyo National Museum in Ueno, where visitors from around the world can admire its delicate beauty and contemplate the spiritual beliefs that inspired its creation more than 1,200 years ago.

What Is a Bone Repository Vessel?

A bone repository vessel (kotsuzōki) is a container used to hold cremated remains in ancient Japan. The practice of cremation was introduced to Japan through Buddhism, and by the Nara period it had become an established funerary custom among the elite. These vessels were often crafted from precious materials and designed with great care, reflecting both the social status of the deceased and the religious significance of the burial.

The bone repository vessel from Miyajidake Shrine is particularly notable for its ingenious triple-layered construction. At the center is a small blown-glass jar known as a ruri-tsubo (lapis lazuli vessel), measuring approximately 112 millimeters in height. This delicate glass container was placed inside a lidded cast-bronze vessel (dō-tsubo) measuring about 195 millimeters. The bronze vessel, in turn, was enclosed within an outer earthenware deep bowl. This three-tiered nesting design served both practical and symbolic purposes, protecting the precious contents while embodying the layered spiritual significance of the burial.

Why Was It Designated a National Treasure?

The bone repository vessel was designated as a National Treasure on April 27, 1961, under the official name "Bone Repository Vessel Excavated from the Precincts of Miyajidake Shrine, Chikuzen Province" (Chikuzen no Kuni Miyajidake Jinja Keidai Shutsudo Kotsuzōki). Several factors contributed to this prestigious designation:

• The triple-layered structure of glass, bronze, and earthenware is an extremely rare example of Nara-period funerary art, demonstrating the sophisticated material culture of the era.
• The blown-glass ruri jar exhibits characteristics of Hakuhō-period (late 7th century) glassmaking techniques, providing important evidence of early glass production in Japan and cultural exchange with the Asian continent.
• The lid of the bronze vessel features a jewel-shaped knob (hōju form), a design element shared with other Hakuhō-period glass vessels, helping scholars trace the evolution of Buddhist-influenced funerary customs in Japan.
• The artifact bridges the transition from the Kofun period to the Nara period, offering crucial archaeological evidence of the shift from burial to cremation among the ruling classes of northern Kyushu.

This bone repository vessel is designated separately from the other famous National Treasure associated with Miyajidake Shrine—the Miyajidake Kofun Excavated Items, which include magnificent gilt-bronze horse trappings, swords, and glass ornaments from the 6th–7th century tomb. Together, these two National Treasures illustrate the remarkable continuity of elite culture and international connections in this region over several centuries.

The Miyajidake Fire Cremation Tomb

The bone repository vessel was discovered on the western slope of a hill east of the Miyajidake Kofun's stone chamber entrance, at an elevation of approximately 65 meters. In 1938, during tree-planting activities, the glass cinerary urn was found just about 30 centimeters below the surface, nestled inside the paired earthenware bowls which in turn contained the bronze vessel.

Scholars believe the earthenware is from a later period than the glass and bronze vessels, suggesting that the remains were reburied at some point in history. The original tomb structure and its precise location remain unknown. This mysterious reburial adds another layer of intrigue to the artifact, raising questions about the identity of the individual whose remains were so carefully preserved and the circumstances that led to their relocation.

The discovery site lies within the broader context of the Tsuyazaki Kofun Group, a cluster of ancient tombs spanning the 5th to 7th centuries built by the powerful Munakata clan, who controlled maritime trade routes across the Genkai Sea to the Korean Peninsula and mainland China.

Highlights and What to Look For

When viewing the bone repository vessel at the Tokyo National Museum, several features deserve special attention:

• The Ruri (Glass) Jar: The inner glass vessel, measuring just 112 millimeters, was created using the blown-glass technique. Its translucent quality and the delicate form of the lid with a jewel-shaped finial are characteristic of Hakuhō-period glasswork. Glass was an exceedingly rare and precious material in ancient Japan, often associated with continental trade and Buddhist ritual.
• The Bronze Vessel: The cast-bronze outer container stands 195 millimeters tall. Although the lid has become fused to the body over the centuries and there is some damage to the base and midsection, the vessel retains its elegant form. The jewel-shaped knob on the lid is clearly visible and provides an important stylistic link to other dated examples.
• The Triple-Nested Structure: The concept of placing containers within containers reflects a deeply held belief in the sanctity of the remains and the desire to protect them through multiple layers of material and spiritual shielding.

The artifact is displayed in the Heiseikan (Japanese Archaeology Gallery) of the Tokyo National Museum, where it can be appreciated alongside other archaeological National Treasures. Please note that as archaeological materials, these items may have longer display periods than paintings or textiles, but it is always advisable to check the museum's current exhibition schedule before visiting.

Miyajidake Shrine and the "Underground Shōsō-in"

While the bone repository vessel itself is displayed in Tokyo, the story of this National Treasure is inseparable from Miyajidake Shrine and its remarkable ancient tomb. The shrine, located in Fukutsu City, Fukuoka Prefecture, is the head shrine of all Miyajidake shrines across Japan, attracting over 2.2 million visitors annually.

Founded according to tradition approximately 1,700 years ago, the shrine is dedicated to Empress Jingū (Okinagatarashihime no Mikoto). The Miyajidake Kofun, a massive circular tomb with Japan's second-longest stone chamber at 23 meters, was discovered in the mid-18th century within the shrine precincts. The over 300 artifacts excavated from this tomb—including gilt-bronze horse trappings, enormous ceremonial swords, green glass beads and plates—have earned it the nickname "the Underground Shōsō-in," a reference to the famous imperial treasure house in Nara.

The shrine is also famous for the "Path of Light" (Hikari no Michi), a phenomenon that occurs twice a year when the setting sun aligns perfectly with the stone steps and the straight approach road extending to the Genkai Sea. The shrine also boasts Japan's largest shimenawa (sacred straw rope), weighing five tons and stretching 13.5 meters.

Nearby Attractions

Visitors to the Tokyo National Museum can combine their viewing of the bone repository vessel with numerous other attractions in the Ueno area:

• Ueno Park: One of Tokyo's most famous parks, home to multiple museums, temples, a zoo, and beautiful seasonal scenery including cherry blossoms in spring and lotus flowers in summer.
• National Museum of Western Art: A UNESCO World Heritage building designed by Le Corbusier, located adjacent to the Tokyo National Museum.
• Ueno Tōshō-gū Shrine: A stunning 17th-century shrine dedicated to Tokugawa Ieyasu, featuring gold leaf decoration and a beautiful peony garden.
• Ameyoko Shopping Street: A vibrant market street near Ueno Station offering everything from fresh seafood to clothing and souvenirs.

For those inspired to visit the original site of discovery, Miyajidake Shrine in Fukutsu City, Fukuoka Prefecture, is accessible from JR Fukuma Station by Nishitetsu Bus (alight at Miyajidake Jinja-mae stop). The shrine's stone chamber (Fudō Shrine) can be visited as part of the Oku no Miya Hachisha pilgrimage route within the shrine grounds.