an Entity references as follows:
The Shinpōinyama Kofun group (新豊院山古墳群, Shinpōinyama kofun-gun) is cluster of kofun burial mounds dating from the late Yayoi to the early Kofun period located in the Mukasatakenouchi neighborhood of the city of Iwata, Shizuoka in the Tōkai region of Japan. The site was designated a National Historic Site of Japan in 1987.