Megalithic mound (tumulus with integral stones)
Asahiyama Kofun
DatedEst. 250–650 CE
Photo Saigen Jiro · CC0Source file on Wikimedia Commons
Overview
About this site
What the sources say
朝日山古墳（あさひやまこふん）は、愛媛県四国中央市金田町金川にある古墳。形状は円墳。愛媛県指定史跡に指定されている。
Article in JapaneseRead on Wikipedia2 min readCC BY-SA 4.0
Where it sits in time
The site's dated range, placed against world reference points.
The scale is logarithmic: each step to the left is about ten times older than the last.
The full article
Asahiyama Kofun: the whole story
In briefSources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
Asahiyama Kofun is a circular burial mound in Kanagawa, Shikokuchuo City, Ehime Prefecture, Japan. It stands on a ridge of the Hara Mine Hills overlooking the eastern Umo Plain and has been designated an Ehime Prefectural Historic Site.
The mound measures 17 meters in diameter and 4.5 meters in height, with a moat-like feature around it. Its burial chamber is a two-sided horizontal stone chamber opening to the southeast. The inner chamber, inner gate, passage and outer gate all survive in good condition, making the chamber particularly valuable.
The chamber is 7.0 meters long. Its inner chamber measures 4.5 meters by 2.0 meters by 2.4 meters, while the 2.5-meter-long passage measures 1.6 meters wide and 2.0 meters high. Crystalline schist forms the lower walls, with smaller stones stacked above. Sue pottery was found as grave goods, but most of it has since been lost.
The mound was probably built in the late 6th or 7th century, within the broader period 250 CE to 650 CE. It was designated an Ehime Prefectural Historic Site on 1968 (Showa 43) March 8. A similar mound once stood 400 meters to the southwest, but it is now almost entirely lost.
No English Wikipedia article exists for it; the full text below is the Japanese article "朝日山古墳", shown in the original language.
Summary in EnglishSources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
Asahiyama Kofun is a megalithic mound (tumulus with integral stones) in Shikokuchūō-shi, Japan. A typological estimate: 250 CE to 650 CE. No English Wikipedia article exists for it; the full text below is the Japanese article "朝日山古墳", shown in the original language.
概要Sources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
愛媛県東部、宇摩平野を一望する原峰丘陵尾根上に築造された古墳である。
墳形は円形で、直径17メートル・高さ4.5メートルを測る。墳丘周囲には周溝状の遺構が認められる。埋葬施設は両袖式の横穴式石室で、南東方向に開口する。玄室・玄門・羨道・羨門が良好な状態で完存する点で貴重な石室になる。副葬品としては須恵器があったが、現在までにほとんどが散逸している。築造時期は古墳時代後期の6世紀後半（または7世紀代）頃と推定される。
古墳域は1968年（昭和43年）に愛媛県指定史跡に指定された。なお、本古墳の南西400メートルにも同様の古墳が存在したが、現在はほぼ失われている。
埋葬施設Sources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
埋葬施設としては両袖式横穴式石室が構築されており、南東方向に開口する。玄室・玄門・羨道・羨門が完存する。石室の規模は次の通り。
石室全長：7.0メートル
玄室：長さ4.5メートル、幅2.0メートル、高さ2.4メートル
羨道：長さ2.5メートル、幅1.6メートル、高さ2.0メートル
石室の石材は結晶片岩。下半分は割石を垂直に立てることで腰石とし、その上に小型の石を持ち送って積み上げる。奥壁には一枚石が使用される。玄門・羨門はいずれも両側に石柱を持つ門構造であり、その形態から羨道部を前室、玄室部を後室とする複室構造の石室の可能性も指摘される。
文化財Sources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
愛媛県指定文化財
史跡
朝日山古墳 - 1968年（昭和43年）3月8日指定。
参考文献Sources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
史跡説明板（愛媛県教育委員会・川之江市教育委員会設置）
「朝日山古墳」『日本歴史地名大系 39 愛媛県の地名』平凡社、1980年。ISBN 4582490395。
How this page was madeSources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
The summary at the top of this page was written by MiniMax-M3 (2026-11-08) from the cited Wikipedia article “朝日山古墳”, translated from Japanese. The numbers in it were checked automatically against the source text. The rest of the page is the article itself, the structured records and computed distances.
Tradition and region
About this kind of monument
Japanese kofun tumuli
Kofun are the great burial mounds of ancient Japan, built mainly between the middle of the third century and the early seventh century CE. The period takes its name from them. The most distinctive form is the keyhole-shaped mound (zempō-kōen-fun), with one square end and one round end seen from above, but there are also plain round mounds, double-rectangle mounds and square mounds. Orientation is not fixed: in the Mozu group at Sakai, some round parts face north and others east.
The largest is Daisenryō kofun at Sakai in Osaka, the biggest kofun in Japan, thought to have been built over some twenty years in the middle of the fifth century. By common acceptance it is the tomb of Emperor Nintoku, and the Imperial Household Agency treats it as such, but this cannot be confirmed because the mound has not been excavated. It stands in the Mozu group, which once had more than a hundred tombs of which fewer than half remain; the group and the neighbouring Furuichi cluster were inscribed on the UNESCO World Heritage List in 2019. The mounds were built on a plateau overlooking Osaka Bay, near the ancient coastline.
Dating rests on mound shape, pottery and grave goods. Haniwa, which means "clay circle", are terracotta cylinders and figures of houses, animals and people that were arranged in rings and rows around and on top of the mounds. Smaller kofun are very numerous and sit in groups in every region of Japan.
When visiting, look for the moat that surrounds the larger mounds, for the stepped outline of terraces, and for reconstructed haniwa in museums and parks beside the tombs.
Paraphrased from Wikipedia: Kofun, Wikipedia: Daisen Kofun, Wikipedia: Haniwa, Wikipedia: Mozu Tombs · CC BY-SA 4.0
See it in 3D
An interpretive reconstruction of the monument, standing on the real ground at its exact point, under the sun for that place and season. Drag to look around it.
The reconstruction is ours, not a survey: it shows what a monument of this type looks like, at the size the record gives for this one.
Photographs
6 photographs, each with its author and licence
More photographs
Lore
Evidence & Lore
What the sources actually support — and, kept apart, what has been claimed.
What the evidence supports
Dates
Est. 250–650 CEHow this date was established: Type comparisonTypical range for megalithic mounds in Japan; this site has not been dated itself. Japanese kofun burial mounds were mainly constructed between the middle of the 3rd century and the early 7th century AD.Source for this date
Where it stands
Japan
The pin marks the monument itself — its exact point.
- Coordinates
- 33°58′41″ N, 133°35′13″ EFor a GPS or map app: 33.97803, 133.58689
Access is as our sources describe it; we have not visited the site to check.
Nearby
The closest sites in the Atlas, by straight line.
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Sources
Every record behind this page, with the link it came from.
2 sources behind this page
- 01Wikidata Q104150547wikidata.org
- 02Source for this dateen.wikipedia.org
Image files
- Asahiyama Kofun, entrance.jpgSaigen JiroCC0
- Asahiyama Kofun, gaikan.jpgSaigen JiroCC0
- Asahiyama Kofun, genshitsu-1.jpgSaigen JiroCC0
- Asahiyama Kofun, genshitsu-2.jpgSaigen JiroCC0
- Asahiyama Kofun, sendou-1.jpgSaigen JiroCC0
- Asahiyama Kofun, sendou-2.jpgSaigen JiroCC0
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Around this place
The ten nearest sites, by compass
Credit
Text, licence and sources
Text from the Wikipedia article "朝日山古墳" (Japanese), licensed CC BY-SA 4.0; authors are listed in the page history. Reused under CC BY-SA 4.0. Read on Wikipedia · Edit history and authors
- Wikipedia (Japanese): 朝日山古墳CC BY-SA 4.0
- Wikidata Q104150547CC0