A burial chamber believed to be the oldest in Japan has been excavated from a tomb in Nara Prefecture, researchers announced Monday.
Wooden beams surrounding a coffin in the 80-meter-long Hokenoyama tomb in the city of Sakurai apparently date from the middle of the third century, said Takayasu Higuchi, head of the prefectural Archaeological Institute of Kashihara.
The chamber measures 7 meters by 2.7 meters and is believed to have housed a coffin measuring 5 meters long by 1 meter wide, which was surrounded by vertical beams and a number of round stones, Higuchi said.
Kunihiko Kawakami, a senior researcher at the institute, said he believes the occupant of the coffin was a powerful local leader belonging to the generation of the father or grandfather of Empress Himiko, who ruled Yamatai Kingdom in the mid-third century. He said the tomb was completed between 220 and 230 AD.
The keyhole-shaped tomb, which has a rectangular area at one end and a raised area at the other, is typical of tombs from primitive Japan in which high-ranking people were buried.
The chamber was found below the floor of the raised area, Higuchi said.
A mirror believed to have been presented by the third-century Wei Kingdom in China to Himiko was also found, Higuchi said.
The discovery of the mirror suggests the possibility that Himiko's Yamatai Kingdom was located in the prefecture. There has been a long dispute over whether the kingdom was based in Kyushu or in an area covering Nara, Kyoto and Osaka prefectures.
Higuchi said the mirror is one of 100 similar ones that Wei presented to Himiko in 240 AD.