Shimosato Kofun: A Keyhole-Shaped Burial Mound in Japan
Site at a Glance
- Rating
- 4.8
- Popularity
- Very Low
- Country
- Japan
- Primary era
- Classical
- External website
- Open
- Eras represented
- Classical
- Civilizations
- Yamato
- Site type
- Burial
- Remains
- Burial Mound
On this page6 sections
History
Shimosato Kofun is a Kofun-period burial mound in Japan, located in Shimosato, Nachikatsuura, near the mouth of the Ota River. Built in the late fourth or early fifth century, during the middle Kofun period, it has the characteristic keyhole-shaped form known in Japanese as a zenpō-kōen-fun, combining a circular rear section with a square front section. It is the southernmost keyhole-shaped burial mound on Honshu and the only known example of this form in the southern Kii Peninsula.
Construction and regional importance
The mound was built on a coastal plain that had been a sand dune at the time of construction. Its isolated position, in a region with relatively few known remains from the Kofun period, provides evidence for examining the historical character of the southern Kii Peninsula. Shimosato Kofun has also been considered in relation to the Kumano kuni no miyatsuko, a hereditary local official or ruler associated with the Kumano area of ancient Kii Province.
Later use and investigation
From approximately the late Heian period through the Meiji period, a Shinto shrine stood on the mound’s square front section. Building the shrine flattened the upper surface of that part of the mound. In 1929, local villagers excavated the site and recovered burial goods, much of which was later dispersed. The first formal archaeological excavation followed in 1974, with additional investigations in 2000 and 2005. The 2000 investigation established the mound’s total length. The kofun precinct became a National Historic Site of Japan on February 24, 1976, and its excavated materials were designated Tangible Cultural Properties of Nachikatsuura Town on February 23, 2012.
Remains
Shimosato Kofun is a small, underdeveloped keyhole-shaped mound approximately 40 meters long. Its circular rear section and square front section are arranged along an east-west axis, with the front section facing west. Surface stones known as fukiishi, which helped protect and stabilize the earthen mound, have been found on the structure. Traces of a moat about 5 meters wide occur around the mound, although its original extent around the entire structure remains uncertain.
Burial chamber
A pit-type stone burial chamber was built at the summit of the circular rear section. It follows the mound’s east-west axis and may have held the deceased with the head toward the east. The chamber is 5.35 meters long overall and has an internal length of 4.75 meters. Its east wall measures 0.95 meters in width and its west wall 0.65 meters. The ceiling stones and most of the north wall have been destroyed. A wooden coffin is believed to have occupied the chamber and was apparently damaged during the 1929 disturbance and excavation.
Burial goods and pottery
Excavations and earlier disturbance produced 56 glass beads, an iron sword, fragments of two other swords, a large jadeite ball, six jadeite tubes, and additional iron objects. Bronze mirrors, including one with an inner floral design, were reportedly recovered in 1929, but their present whereabouts are unknown. Pottery from the mound includes Jomon and Yayoi vessel fragments, a double-rimmed jar probably associated with the mound’s construction, and a Haji pottery jar from the same period. Haji pottery was an unglazed earthenware made in ancient Japan. Heian- to Muromachi-period pottery, including vessels connected with salt making, also occurs at the site. Some early pieces reflect influence from, or possible importation from, the Tōkai region, while the later material indicates disturbance or contamination during the premodern period.
