| Location | Nara Pref. |
|---|---|
| Shape | Scallop-shaped mound |
| Mound length | 130 m |
| Period | Mid 5th c. |
130m scallop-shaped mound in Koryo Town, within Umagami Hills Park.Located within the public Mamikyu Ryoko Park. The romantic name "Otomeyama" (Maiden Hill) is attributed to the graceful shape of the mound. Scallop-shaped mounds are generally considered one rank below keyhole mounds, suggesting this was the tomb of a powerful figure subordinate to Suyama Kofun.
IHA-designated reference site (for Prince Yamato-hiko); excavation prohibited, access restricted. From external survey, the scallop-shaped (hotategai-gata) form with a significantly shortened front section is confirmed. Estimated dimensions: rear circle ~100m diameter, ~13m high; total length ~130m. Confirmed as the largest scallop-shaped mound in Nara Prefecture based on external observation. A tsukuridashi (ritual annex) is reported on the west side of the rear circle, but details are unclear. Burial chamber and grave goods unconfirmed. Within the 5th-century Umagami group, this mound is considered the leading example of the scallop form in scale and status.