| Location | Nara Pref. |
|---|---|
| Shape | Keyhole-shaped mound |
| Mound length | 200 m |
| Period | Early 5th c. |
200m mound in Koryo-cho. Located in the northern section of Mamikyu Ryoko Park. Managed by the IHA as a mausoleum reference site.Located near Otomeyama and Nagareyama Kofun within Mamikyu Ryoko Park.
IHA-designated reference site (Miyoshi Ryobo Sankochi); excavation prohibited. From exterior survey, the three-tiered mound form is confirmed; traces of stone paving and cylindrical haniwa rows have been reported from surface observation and collection. The basic structure of the 200m keyhole mound with surrounding moat is established. Internal burial chamber and grave goods unknown. Located in the northern section of Umagami Hills Park, forming the central Umagami group together with Suyama Kofun (220m) and Otomeyama Kofun (130m). Its restricted IHA status contrasts with the neighboring Suyama Kofun (Special National Historic Site), which has undergone full archaeological investigation.