Joganjiyama Kofun is a square mounded tomb constructed on the west side of the square front part of Hakayama Kofun [38], adjacent to its outer bank. Given the position of the mound, this tomb is considered to be related to Hakayama Kofun.
The mound length is 67 m, and its height is 9.7 m.
The construction period dates to the first half of the 5th century.