Ōda Chausuyama Kofun

The mound stands on the Tomita plateau on the right bank of the Yodo River, and its front part faces south. It is built in three tiers (according to one view, four) and has a length of 226 metres. The round rear part is 138 metres in diameter and 19.2 metres high; the front part is 147 metres wide and 19.8 metres high. Projections (tsukuri-dashi) lie at the waist of the mound on both sides. A shield-shaped moat about 28-33 metres wide surrounds it, and outside the moat runs an embankment 30 metres wide. The condition of the mound and moat is poor.

Five probable satellite tombs (baizuka) have been lettered A to E by the Osaka Prefectural and Ibaraki City boards of education. Mound A is a round mound about 21 metres in diameter. Mound B is a round mound with a projection, about 19 metres in diameter and about 4 metres high. Mound C is a keyhole-shaped mound about 28 metres long. Mound D, measuring 20 metres north to south by 14 metres east to west and about 3 metres high, shows no traces of a ditch or haniwa, so it is uncertain whether it is a satellite tomb. Mound E is a square mound about 27 metres on a side, from which no finds came.

Excavations outside the moat were carried out by the Osaka Prefectural Board of Education and the Ibaraki City Board of Education in 1972 and 1988, and in 2002 the Imperial Household Agency's Archives and Mausolea Department excavated at the foot of the mound. The work recovered cylindrical haniwa and figure haniwa, including house, human, armour, horse and cormorant forms from the northern embankment. The haniwa are attributed to the Niiike (新池) haniwa production site at Kamitsuchimuro, Takatsuki, whose oldest kiln group A matches them; the production site itself is thought to have begun operating when this mound was built.