Akamon-ue Kofun (赤門上古墳) is a keyhole-shaped kofun burial mound located in the Uchino district of Hamakita-ku, Hamamatsu, Shizuoka Prefecture Japan. It is protected by the prefectural government as a national historic site. Located on the eastern edge of the Mikatahara plains and near the Tenryū River, the Akamonue Kofun is only one of several kofun in the same district. It takes its name from the red gate of a nearby Buddhist temple, which was built at a much later date. The name or rank of the person buried in the tomb, which dates from the latter half of the 4th century is unknown.