Kōmyōsan Kofun
The is a"kofun" burial mound located in the Yamahigashi neighborhood of Tenryū-ku, Hamamatsu, Shizuoka Prefecture in the Chūbu region of Japan. The tumulus was designated a National Historic Site of Japan in 2020. Overview. The Kōmyōsan Kofun is a , which is shaped like a keyhole, having one square end and one circular end, when viewed from above. The tumulus is located at the tip of a tongue-shaped hill of the Tenryū River plain in western Shizuoka prefecture, and is one a group of several tumuli. The cluster of tumulus is named for a Buddhist temple in  the vicinity. It was discovered in 1939, and was made a Shizuoka Prefectural Historic Site in 1955. An archaeological excavation was conducted from 2017 to 2018. The tumulus is orientated to the south, and has an overall length of 83 meters, making it the largest in Hamamatsu City. The anterior circular portion has a diameter of 45 meters and a height of 7.5 meters and is constructed in two tiers. "Fukiishi" and "haniwa" have been found on the surface of the mound; however, the burial chamber remains undiscovered, as the main body of the mound was not excavated. The construction  period is estimated to be around the middle of the 5th century, or the middle of the Kofun period. The Kōmyōsan No.2 Kofun located to the south was a circular tumulus with a diameter of 33 meters but it has now been destroyed.