The Hirumeshi Otsuka Kofun, located in Hirumeshi-cho, Ogaki City, Gifu Prefecture, is the largest keyhole-shaped burial mound in Gifu Prefecture, reaching an overall length of approximately 150 meters. It is believed to have been constructed in the first half of the fifth century and is regarded as the tomb of a powerful chieftain who ruled the Nobi Plain. Archaeological excavations have confirmed…

Built in the first half of the 5th century. It is the largest keyhole-shaped burial mound in Gifu Prefecture, with an overall length of approximately 150 meters, believed to be the tomb of a chieftain who ruled the Nobi Plain. Designated a National Historic Site. Excavations have confirmed the prese…