is a
Kofun period
The is an era in the history of Japan from about 300 to 538 AD (the date of the introduction of Buddhism), following the Yayoi period. The Kofun and the subsequent Asuka periods are sometimes collectively called the Yamato period. This period is ...
burial mound, located in the city of
Awaiwa,
Okayama Prefecture
is a Prefectures of Japan, prefecture of Japan located in the Chūgoku region of Honshu. Okayama Prefecture has a population of 1,906,464 (1 February 2018) and has a geographic area of 7,114 Square kilometre, km2 (2,746 sq mi). Okayama Prefectur ...
, in the
San'in region of
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
. The tumulus was designated a
National Historic Site of Japan in 1924 with the area under protection expanded in 1978 and again in 2006.
It is largest
keyhole-shaped burial mound in the
Bizen region and the third largest in Okayama Prefecture, and the 39th largest in Japan.
Overview
The Ryōgūzan Kofun is a , which is shaped like a keyhole, having one square end and one circular end, when viewed from above. It is part of the Ryōgūzan Kofun cluster (also known as the Nishi-Takatsuki Kofun cluster) which consists of four keyhole-shaped tombs and two scallop-shaped tombs, including this one.
Built in the latter half of the 5th century, or the middle of the Kofun period, the Ryōgūzan Kofun has a surrounding moat and a total length of 206 meters. An
archaeological excavation
In archaeology, excavation is the exposure, processing and recording of archaeological remains. An excavation site or "dig" is the area being studied. These locations range from one to several areas at a time during a project and can be condu ...
from 2002 to 2004 discovered a new moat around the outside of the surrounding moat, revealing that the original construction had a double moat. Including the two surrounding moats, the total length of the burial mound reaches 349 meters on the main axis. The outer moat is buried under surrounding
paddy field
A paddy field is a flooded field (agriculture), field of arable land used for growing Aquatic plant, semiaquatic crops, most notably rice and taro. It originates from the Neolithic rice-farming cultures of the Yangtze River basin in sout ...
s, but the inner moat is still filled with water (and is used as a reservoir for agriculture). The tumulus itself is about 120 meters wide at the anterior rectangular portion, 100 meter in diameter at the posterior circular portion, and about 20 meters high at both portions. No ''
fukiishi
( or "roofing stone") were a means of covering burial chambers and burial mounds during the kofun period of Japan (). Stones collected from riverbeds were affixed to the slopes of raised kofun and other burial chambers. They are considered t ...
'' or ''
haniwa'' have been found. Since the tumulus itself has not been excavated, the details of the
burial chamber are is unknown. The dimensions of the tumulus appear to be based on a two-fifths scale of the
Daisenryō Kofun (tomb of
Emperor Nintoku
, also known as was the 16th Emperor of Japan, according to the traditional order of succession. Due to his reputation for goodness derived from depictions in the Kojiki and Nihon Shoki, he is sometimes referred to as the .
While his existence ...
in
Sakai, Osaka
is a city located in Osaka Prefecture, Japan. It has been one of the largest and most important seaports of Japan since the medieval era. Sakai is known for its keyhole-shaped burial mounds, or kofun, which date from the fifth century and inclu ...
), and indicates that the person buried at the Ryōgūzan Kofun was an influential person with strong ties to theYamato kingdom.
To the north of the Ryōgūzan Kofun is a ''baizuka'' ancillary burial mound, the , with a diameter of about 20 meters and a height of about 5 meters. This smaller tumulus also originally had a double moat, although it appears that part of its outer moat was shared with that of the Ryōgūzan Kofun. Currently, only the round rear part of the mound remains, but excavations confirmed the front part once existed. As with the Ryōgūzan Kofun, no ''fukiishi'' and ''haniwa'' have been found. It is estimated to have been built in the latter half of the 5th century.
The tumulus is about 10 minutes by car from
JR West Seto Station. The
Bizen Kokubun-ji
The was a Buddhist temple located in what is now the city of Akaiwa, Okayama, Japan. It was one of the provincial temples per the system established by Emperor Shōmu during the Nara period (710 – 794) for the purpose of promoting Buddhi ...
ruins are located on the west side of Ryōgūzan Kofun.
Gallery
Ryoguzan Kofun, zenkei-1.jpg, Panoramic view
Wada Chausuyama Kofun, zenkei.jpg, Wada Chausuyama Kofun
See also
*
List of Historic Sites of Japan (Okayama)
This list is of the Monuments of Japan, Historic Sites of Japan located within the Prefectures of Japan, Prefecture of Okayama Prefecture, Okayama.
National Historic Sites
As of 6 August 2019, forty-seven Sites have been Cultural Properties of J ...
References
External links
Akaiwa City home page
{in lang, ja
History of Okayama Prefecture
Akaiwa, Okayama
Historic Sites of Japan
Zenpokoenfun