Ōzuka Kofun: A Decorated Burial Mound in Japan
Site at a Glance
- Rating
- 4.2
- Popularity
- Low
- Country
- Japan
- Primary era
- Medieval
- External website
- Open
- Eras represented
- Medieval
- Civilizations
- Yamato
- Site type
- Burial
- Remains
- Burial Mound
On this page14 sections
History
Ōzuka Kofun is a decorated burial mound in Keisen, Fukuoka Prefecture, Japan, built in the middle of the sixth century during the Kofun period, the era of large elite burial mounds that lasted from about the third to the seventh century. It is a keyhole-shaped mound and the largest of its form in the Onga River basin. Its painted burial chamber and unusual funerary structures make it an important example of Japan’s decorated kofun.
Construction and discovery
The mound was created in the Jumei district, where the front of a hill lies southwest of Mount Kinpira beside the middle reaches of the Honami River, part of the upper Onga River system. It stood within an alluvial plain and was later identified as Jumei Ōzuka Kofun as well as Ōzuka Kofun.
The burial chamber was found by accident on September 30, 1934, during earth excavation for the Mameda coal mine. Workers had been cutting into the hill for about two months when they broke through the stone chamber. More than half of the mound had already been removed, and the area around the chamber entrance had suffered damage. The discovery revealed murals in red, black, green, yellow, and white, together with a stone house-shaped coffin enclosure, a lamp stand, and stone pillows. The combination of a small window, the enclosure, and a projecting stone shelf is exceptionally rare among decorated kofun.
Investigations followed under the Fukuoka Prefectural authorities and Kyoto University. Ōzuka Kofun became a National Historic Site on June 15, 1937. Damage to the murals continued because protection was inadequate. Cracks linked to nearby coal mining were identified in 1948, even as proposals to continue mining around the mound were still being made.
Protection and research
Ōzuka Kofun was elevated to Special National Historic Site status on March 29, 1952. It was the first decorated kofun to receive that designation, and the protected area was enlarged in 1977. More than 100 grave goods were recovered. The group was designated an Important Cultural Property on June 28, 1956, under the collective title “Excavated Objects from Ōzuka Kofun in Kaho District, Chikuzen Province.” The objects are held by the Kyoto National Museum.
Further structural danger emerged in 1966, when cracks were found in the ceiling stone of the front chamber. Supporting pillars were installed the following year to reduce the risk of collapse. Water leakage had also caused mold, so the mound was temporarily covered with compacted earth and protective mats, while ordinary access to the chamber was stopped.
A sixteen-member preservation research group was formed in 1969, combining expertise in archaeology, architecture, civil engineering, conservation science, and meteorology. Its work also informed study of Takamatsuzuka Kofun after that mound was discovered in 1972. In 1980, local volunteers and people interested in archaeology created the Ōzuka Kofun Preservation Association, which obtained financial support for repairs and site organization. A further preservation research committee, chaired by Kyoto University emeritus professor Kobayashi Yukio, then began systematic research.
Preservation and site-organization work started in 1987. Protective facilities were erected over the chamber, along with visitor facilities and measuring instruments. Mound restoration was completed in November 1990, and the adjacent Ōzuka Decorated Kofun Museum opened in November 1994. The burial chamber is normally sealed to protect its paintings, with public openings held twice each year, in spring and autumn.
Remains
Mound and earthworks
Keyhole-shaped mound
Ōzuka Kofun has the form known as a zenpo-koen-fun, or keyhole-shaped mound, with a rectangular front section joined to a circular rear section. Its reconstructed or estimated total length is about 85 to 86 meters. The rear circular section measures about 56 meters across and rises approximately 9.5 meters high, while the front section is about 60 meters wide. A topographic reconstruction has produced an original length of about 78 meters.
Layered construction and enclosure
The mound was built in two tiers. Ordinary soil forms the lower layer, while the upper section uses alternating layers of yellow and black soil packed into place. Parts of the slopes were faced with rounded stones. Cylindrical and figurative clay haniwa, objects placed on or around some burial mounds, were found at the site. A double moat and an earthwork embankment enclosed the mound.
Stone burial chamber
Entrance and front chamber
The burial facility is a horizontal-entry stone chamber, reached through a passage cut into the side of the mound, and it faces northwest. Its classification varies: some descriptions treat it as one chamber with side extensions and an entrance passage, while others distinguish a front chamber or passage from a rear chamber, also called the inner chamber. The difference depends on whether the passage is counted as a separate room. The front chamber or passage is approximately 1.97 meters long, 2.8 meters wide, and 2.17 meters high.
Inner chamber and funerary fittings
The rear, or inner, chamber measures about 4.43 meters long, 3 meters wide, and 3.72 meters high, giving the entire stone chamber a length of approximately 6.75 meters. Five granite slabs form its foundation, and irregularly stacked stones complete the structure. A small window was set above the entrance.
At the rear wall, a stone house-shaped enclosure covered the coffin. It provided room for two bodies and contained two depressions for their heads. Two additional stone pillows stood outside the enclosure, and four people are therefore estimated to have been buried in the chamber. A massive stone shelf, about 0.5 meters thick, projects above the enclosure. A lamp stand was also placed in the rear chamber.
Painted decoration
Colors and entrance imagery
Murals cover almost the entire interior, with the left and right walls of the front chamber or passage forming the stated exception. The five colors used are red, black, green, yellow, and white. This is the highest number of mural colors recorded for a Japanese decorated kofun and represents all but blue of the six colors identified in such murals nationally. Clay provided the principal coloring material.
On each side of the entrance to the inner chamber, five red and black horses appear with harnesses and very small riders. Their arrangement has been compared with a guard. The entrance and lamp stand carry double-legged wheel designs and curling, fern-like warabi motifs. Warabi patterns, double-legged wheels, concentric circles, and triangles continue around the entrance.
Weapons and symbolic designs
The front and left walls of the inner chamber contain 24 images of quivers. The right wall has 11 shields, six sword designs, and two bow designs. Eight more quiver motifs appear on the rear wall and around the lamp stand. The stone house-shaped enclosure is decorated with triangular patterns and warabi motifs. Above it, the inner chamber is painted red and covered with yellow circular dots representing stars. Apart from Ōzuka Kofun, seven other kofun in Japan are stated to have warabi motifs.
Grave goods
The excavated objects include horse equipment such as a saddle, stirrups, and pendant fittings. Other finds comprise a deformed divine-beast bronze mirror associated with hemp-like textile, tubular, natsume-shaped, cut-faceted, and small beads, earrings, silver bells, a lapis-lazuli tubular bead, wooden beads with metal inlay, earthen beads, an amber bead, and a gold object.
Weapons and military equipment include swords, spears, knives, iron arrowheads, and fragments of scale armor. Ceramics consist of Haji ware and cups and jars of Sue ware. The collection is preserved at the Kyoto National Museum.
