The city of Yamato-Kōriyama (大和郡山市) in Nara Prefecture has reported new findings from excavations at the Wari-zuka
Kofun (割塚古墳), a round burial mound (円墳
enpun) dating to the early sixth century in Sennichi-chō (千日町). Archaeologists confirmed that the horizontal stone burial chamber (横穴式石室
yokōana-shiki sekishitsu) and its stone coffin remain in good condition.
Warizuka Kofun (割塚古墳) is a Japanese burial mound located in Yamatokoriyama, Nara Prefecture.
- Time Period: The tomb dates to the early 6th century (Late Kofun period).
- Structure: It is a circular mound (enpun) approximately 49 meters in diameter.
- The Stone Coffin: The coffin seen in the image is a house-shaped stone coffin (kurinuki-shiki type) carved from tuff stone from Mt. Nijo.
- History: The tomb was first excavated in 1968 due to residential development, after which it was reburied for preservation. It has recently undergone re-excavation to investigate its structure.
The mound was first excavated in 1968 by the Nara Prefecture Kashihara Archaeological Institute (奈良県立橿原考古学研究所) during residential development. It measures about 49 metres in diameter and roughly 4.5 metres in height. The excavation produced numerous grave goods (副葬品), including earrings thought to have come from the Korean Peninsula, bronze mirrors, beads and horse fittings.
The site was designated a municipal historic monument in 1978 and later incorporated into a park. Parts of the mound have collapsed in recent years. The city began a new investigation in fiscal 2021 as part of plans to stabilise the site.
Work first reopened the approach corridor, or sendō (羨道), which leads to the burial chamber. This year, archaeologists examined the chamber itself. It measures about 6.6 metres in length and three metres in width. The upper portion, including the ceiling, has disappeared. Walls remain to a height of about 1.4 metres.
The chamber rests on a base of tightly packed stones, roughly the size of a human head. Ono Daisuke, a curator involved in the project, believes the layer served as ground reinforcement to support the weight of the chamber and coffin.
A stone coffin carved from tuff quarried at Mount Nijō (二上山) stands in the centre. It measures about 2.7 metres in length. The coffin and the surrounding chamber appear little changed from their condition when archaeologists first recorded them nearly sixty years ago.
Researchers also identified a structure behind the rear wall of the burial chamber (玄室
genshitsu). The discovery came during excavations that began in February. A narrow passage about 3.5 metres long and one metre wide runs behind the wall. The corridor is lined with stonework.
Examples of such rare passages are rare. According to the city, only one comparable case has been documented locally, at the Ichio-Hakayama Kofun (市尾墓山古墳) in Takatori (高取町), built in the early sixth century. That corridor is thought to have been used to bring in the stone coffin's lid during construction.
The Wari-zuka corridor is narrower than the coffin, which measures about 1.4 metres across. Its function remains uncertain. City officials believe it may have been used during the construction of the chamber, during burial rites, or possibly both. Once the chamber was completed, the passage would have been sealed and hidden from view.
Part of the rear structure became visible because later park construction damaged the mound. Archaeologists say the exposure offers an unusual chance to study the hidden structure behind the chamber.
Earlier work in fiscal 2024 confirmed that the stone coffin at the summit of the mound remained well preserved. The reconstructed mound rises about 10 metres above the surrounding residential area. The exposed coffin attracted attention for its striking position above the neighbourhood and was sometimes described as resembling a "stone coffin in the sky".
The city plans to complete the series of investigations begun in fiscal 2020 and prepare a full excavation report in fiscal 2026. Attention will then turn to how the coffin and the site's unusual location can be preserved and used in the future.
Translated from here:
奈良県大和郡山市まちづくり戦略課は26日、1968年の発掘調査後、埋め戻して保存していた同市千日町の円墳、割塚古墳(市史跡、6世紀前半)を再発掘し、横穴式石室や石棺が良好に保存されているのを確認した…
奈良県大和郡山市は11日、古墳時代後期(6世紀前半)の円墳「割塚古墳」(千日町)で、石棺が置かれた玄室の奥壁の背面で通路などを確認したと発表した。市によると、石室の外の調査自体が珍しく、同様の背面通路確認は市尾墓山古墳(高取町)に次いで2例目。通路の性格や役割は不明だが、横穴式石室の構築技法やこの