Togo Takatsuka Kofun (Toga Takatsuka Kofun) was surveyed and trenched survey conducted between 1986 and 1988 as a survey on important remains. In the Kofun period, a keyhole-shaped tumulus measuring 64.4 m in total length built around the latter half of the 4th century, the burial facility houses a long split bamboo-shaped coffin with an inner law of about 5.4 m. As the national ritual at Okinoshima begins, it is a keyhole-shaped tumuli suddenly appeared in the inland area, and it is believed that the buried person is a person who has some sort of involvement in the early Okinoshima ritual.