Gobyoyama Kofun is a keyhole-shaped mounded tomb located in the central part of the Mozu area.
The mound length is 203 m, and the height of the round rear part is 18.3 m.
It is surrounded by a single moat, but it had a double moat when originally constructed.
During the excavations, cylindrical haniwa (earthenware funerary sculptures) were found on the first-tier terrace, arranged without gaps, and a wide variety of artifacts have been excavated from the projection, such as enclosure- and house-shaped haniwa and clay objects representing fish and baskets.
The construction period dates to the mid-Middle Kofun period.