Ichiniwa Tumulus (市庭古墳)

Ichiniwa Tumulus is a megalithic tomb which lies across Tsukamoto and Ichiniwa, Saki-cho, Nara City, Nara Prefecture. It belongs to the east group of the Sakitatenami burial mounds, and is located at the western end of the group. Although it is a large keyhole-shaped tomb mound, its front square part has disappeared, and only a part of its rear round part remains now.


File of Ichiniwa Tumulus - 1

Ichiniwa Tumulus is immediately adjacent to the north of the traces of Daigokuden (Council Hall in the Imperial Palace) in Heijo-kyu Palace, and it was once thought to have been one of the largest circular tomb mound whose diameter was over 100 meters. But the later excavation and research has revealed that its front square part had been removed and leveled out when Heijo-kyu Palace was constructed, and that the original tumulus had been a keyhole-shaped tomb mound with its front square part facing south, whose total length was 253 meters with its front square part being 164 meters in width and its rear round part being 147 meters in diameter. What is more, fuki-ishi (stones covering an old tomb), tsukuridashi (narrow terraces) at the both sides of the central narrow part, and a part of the double moats have also been distinguished.

Another kofun that had been destroyed like Ichiniwa Kofun when Heijo-kyu Palace was constructed is Shimeno Tumulus (117m in total length) which had been located below the second Daigokuden site.

The central part of the rear round part of Ichiniwa Tumulus has been designated as Emperor Heizei's Yamamomo no Misasagi by the Imperial Household Agency.

Construction Time

Ento haniwa (cylindrical clay figures) and dobutsu haniwa (animal-shaped clay figures) have been unearthed. Consequently, it is thought that this tumulus was constructed in the first half of the mid Kofun period (the first half of the fifth century).


Because it is clear that Ichiniwa Tumulus which had existed since before the construction of Heijo-kyo (the ancient capital of Japan in current Nara) is not a tomb mound made for Emperor Heizei who was a person in the Heian period, there are many negative opinions on the authorization of the imperial mausolea. If the authorization is right, it means that a new imperial mausoleum was not made for Emperor Heizei, but he was buried in an existing kofun as the additional deceased.

[Original Japanese]