| Location | Osaka Pref. |
|---|---|
| Shape | Rectangular mound |
| Mound length | 21 m |
| Period | Late 3rd c. |
Rectangular mound in Takatsuki City. Famous for bronze mirrors dated 235 CE. Open to the public as "Seiryu 3rd Year Hill."
1991 excavation by Takatsuki City. The defining find: 5 bronze mirrors inscribed with the year "Seiryu 3rd Year (235 CE)" — designated as Important Cultural Properties. Same-mould counterparts appear at sites across Japan, making these key evidence for the Yamato polity's mirror-distribution network. The specific production year (235 CE) on the mirrors is uniquely valuable. Exhibited at the Takatsuki City Imashiroduka Ancient History Museum; the site is open to the public as "Seiryu 3rd Year Hill."
One of the earliest mounds in Japan, famous for its dated bronze mirrors.