Hidden chamber in 5th-century Japanese burial mound poses new puzzle
Researchers trying to unravel the mystery of who was buried in the late fifth-century Inariyama burial mound in Gyoda, Saitama Prefecture, have a new puzzle to solve after finding a hitherto hidden chamber in the structure.
|An aerial view of the Inariyama burial mound in Gyoda, Saitama Prefecture |
[Credit: Shiro Nishihata]
In 1968, researchers uncovered a sword blade with a gold-inlaid inscription at the site. Called Kinsakumei tekken, the blade is designated as a national treasure and believed to be among the oldest examples of Japanese script in the nation. The inscription refers to King Wakatakeru, who is assumed to have been the Emperor Yuryaku in the fifth century.
Initially, it was assumed that the owner of the sword and the individual buried in the mound were one and the same. But the discovery of another chamber deeper underground and thought to be the original burial site suggests the mound was built for someone else.
|Among items uncovered at the Inariyama burial mound were a sword and bronze mirror |
that were entombed with the deceased [Credit: Asahi Shimbun]
The 73.5-centimeter-long blade, found in the rear circular section of the structure, was in a chamber of small rocks about 1 meter deep. The chamber, located slightly off-center, was fashioned from fist-sized rocks and next to one made of clay.
Researchers also found a bronze mirror, a very precious artifact in the fifth century, military items and metal fragments from horse harnesses. No human remains were found.
The reference to King Wakatakeru had a profound impact as it confirmed the existence of an individual of the same name who appears in classical Japanese histories, such as "Nihon Shoki" (The Chronicles of Japan) and "Kojiki" (Records of Ancient Matters).
Given that the entire site is designated as having national historical significance, it is not possible for researchers to simply dig where they want. For this reason, Motoyuki Sato, a professor of applied electromagnetics at Tohoku University's Center for Northeast Asian Studies, used radar in November to investigate the rear circular section.
|Researchers from Tohoku University use radar technology to investigate the interior of the Inariyama |
burial mound in Gyoda, Saitama Prefecture [Credit: Takuya Kawasaki]
That study picked up a shadow, indicating a lens-shaped structure 4 meters long and 3 meters wide, with a maximum thickness of 1 meter. The chamber lies about 2.5 meters below the surface. There also appears to be a part extending beyond the shadow.
Based on the location and depth, the chamber is thought to be the original burial site. The small rock and clay chambers found nearby may have been created for later generations.
|A lens-like structure lies at the bottom left of this 3-D image based on a radar scan of the area |
[Credit: Motoyuki Sato]
Source: The Asahi Shimbun [December 31, 2016]