Atagozuka Kofun
is a mounded tomb located in the Kōdachi area of Yao, Osaka, in Japan. It is the largest scallop-shaped burial mound, or kofun. It is a round burial mound 22.5 meters in diameter and 9 meters tall. It was constructed in the late sixth century, during the Asuka period.

Later use 

Atagozuka-kofun existed as a grave in the late 6th century and hosted additional burials. After that it also existed as a sacred place for some 200 years. The tomb was reused after the Heian period as shown by the excavation of two pieces of sueki (unglazed ware) of the early Heian period and also of black pottery, unglazed pottery, Hagi plates and hagama (kama with wing) of the middle and later Heian and Kamakura periods. An excavated five-ring pagoda and human bones of the Muromachi period show that this ancient tomb was used for additional burials in the medieval period.

References

Geography of Osaka
Designated historic sites of Osaka Prefecture
Kofun
Round Kofun