Hebizuka Kofun: A Late Kofun-Period Keyhole Burial Mound in Kyoto
Site at a Glance
- Rating
- 4.1
- Popularity
- Low
- Country
- Japan
- Primary era
- Medieval
- External website
- Open
- Eras represented
- Medieval
- Civilizations
- Yamato
- Site type
- Burial
- Remains
- Tomb
On this page10 sections
History
Hebizuka Kofun is a keyhole-shaped burial mound in Japan, built around the end of the sixth century or the beginning of the seventh century during the late to terminal Kofun period. The Kofun period, generally dated from the third to the seventh century, was an era of large burial mounds for members of Japan’s elite. Hebizuka belongs to the last phase of surviving keyhole-shaped mound construction known in Kyoto Prefecture.
The Hata Connection
The mound is associated with the Hata clan, an immigrant-descended lineage linked with the development of the Sagano and Uzumasa areas. The region’s largest mounds are therefore interpreted as possible burials of Hata leaders, although the person buried at Hebizuka remains unknown. Its traditional name, meaning “Snake Mound,” is explained by a story that snakes lived in the stone chamber.
Modern Investigation and Protection
Urban development removed almost all of the mound’s earthen covering, although part of it reportedly survived until around 1920. In 1936, the archaeologist Kōsaku Hamada and researchers from the Archaeological Laboratory of Kyoto Imperial University carried out measured surveys of the mound and its stone chamber. Their findings were reported in 1937 and 1938.
A monitoring investigation during public sewer construction in fiscal year 1988 recovered artifacts from a deposit beneath the stone chamber’s base. These objects date to the fourth quarter of the sixth century and establish the earliest possible date for construction. The stone-chamber area received designation as a National Historic Site of Japan on May 4, 1977.
Remains
Hebizuka was formed as a keyhole-shaped mound, combining a square front section directed toward the southwest with a circular rear section that contained the burial facility. Its estimated overall length was about 75 meters. The earthen covering has disappeared, but the former outline can still be recognized in the arrangement of surrounding residential plots. The exposed stone chamber is the principal surviving feature.
Mound Layout
Keyhole-Shaped Mound
The square front and circular rear sections created the characteristic plan of a keyhole-shaped mound, known in Japanese as a zenpō-kōen-fun. The rear circular section held the burial chamber, while the front section extended toward the southwest. The mound’s surviving spatial outline is expressed through the pattern of nearby residential plots.
Stone Burial Facility
Horizontal-Entry Chamber
The burial facility is a large megalithic, horizontal-entry stone chamber. This type of chamber is reached through a passage opening through the side of the mound rather than through a vertical shaft. Hebizuka’s chamber has projecting side sections where the passage joins the main room, a form known as a double-sleeved chamber. The chamber and passage together measure 17.8 meters and open toward the southeast.
Main Chamber
The main chamber is 6.8 meters long, 3.8 meters wide, and 5.2 meters high, with a floor area of 25.8 square meters. By floor area, it ranks fourth nationally among the largest known burial chambers. Its side walls and rear wall consist of huge stones laid in two or three courses, while one original ceiling stone remains.
Entrance Passage and Stonework
The entrance passage is approximately 11 meters long, 2.6 meters wide, and 3.4 meters high. The chamber was built from chert, a hard, fine-grained sedimentary rock, rather than granite. Chert is widespread in the northern Kyoto mountains, part of the Tamba accretionary complex, a geological assemblage formed from material added to the edge of a tectonic plate. The chamber is comparable in scale to that of Ishibutai Kofun in Asuka, Nara Prefecture, and its width exceeds that of Ishibutai’s chamber.
