One of the Miidani tombs preserved in Tsurugigaoka Park in Yoka, Yabu. Its inscribed sword provides important evidence for dating Kofun-period blades and burial goods. It is part of the Miidani Kofun Group.
Finds & research
103 finds designated Important Cultural Properties, including a copper-inlaid Boshin-year sword (usually interpreted as AD 608; AD 668 has also been proposed). Horizontal stone chamber lacking a distinct shoulder between chamber and passage.
Official status & archaeological view
Official status
Part of the National Historic Site "Miidani Kofun Group" (1992; mounds 2–5).
Archaeological view
A round mound measuring 12m east–west and 14m north–south, with an 8.6m horizontal stone chamber lacking a distinct shoulder between chamber and passage. The Agency for Cultural Affairs’ designation account dates its construction to the end of the 6th–beginning of the 7th century, with at least two later burials through the mid-7th century. Yabu City’s park account instead dates the cluster to the 630s–660s. A copper-inlaid sword inscribed with the Boshin year was found. The Agency for Cultural Affairs’ designation account regards it as a grave good of a later burial, while Yabu City’s excavation account interprets it as an object re-placed from the first floor level. The Agency for Cultural Affairs’ designation account regards the Boshin year as the 16th year of Empress Suiko (AD 608), the most likely date, while Yabu City notes that AD 668 has also been proposed.
Field notes
In Tsurugigaoka Park. Yabu City says visitors can view the inside of the No.2 stone chamber, where replicas such as swords are displayed; the original designated finds are held by the Hyogo Prefectural Museum of Archaeology.