Megalithic mound (tumulus with integral stones)
Hodoyama Kofun Group
DatedEst. 250–650 CE
Photo Saigen Jiro · CC0Source file on Wikimedia Commons
Overview
About this site
What the sources say
宝洞山1号墳（ほうどうやまいちごうふん）または天生津古墳（あもうづこふん）は、愛媛県四国中央市川之江町にある古墳。形状は円墳。宝洞山古墳群を構成する古墳の1つ。四国中央市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
Hodoyama Kofun Group: the whole story
In briefSources for this section
- Wikipedia (Japanese): 宝洞山1号墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 宝洞山1号墳CC BY-SA 4.0
Hodoyama Kofun Group, also known as Hōdōyama Daiichi-gōfun or Amōzuko Kofun, lies at the foot of Hodoyama on the northeastern edge of the Uuma Plain in eastern Ehime Prefecture, Japan. The round mound is one of three in the group and is designated a historic site by Shikokuchūjō City.
The mound measures 20 meters in diameter and 5 meters in height. A moat follows its northern side, cutting into the hillside slope. Its burial chamber is a two-sleeved horizontal stone chamber opening to the south. Built with large stones, it resembles the chamber at Umō Mukōyama Kofun and includes a chamber-door pillar similar to one at Asahiyama Kofun. Grave goods are not clearly known.
No excavation has yet been carried out at the site. The mound is generally dated to the 7th century, at the end of the Kofun period, which lasted from 250 CE to 650 CE. The group also includes No. 2 Kofun, which is almost buried, and No. 3 Kofun, which has almost disappeared.
Monuments of this kind in Japan are large burial mounds built mainly between the middle of the third century and the early seventh century CE. Round mounds are among several forms, alongside keyhole-shaped, double-rectangle and square mounds. The Hodoyama site has been protected as a historic site since 1976.
No English Wikipedia article exists for it; the full text below is the Japanese article "宝洞山1号墳", shown in the original language.
Summary in EnglishSources for this section
- Wikipedia (Japanese): 宝洞山1号墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 宝洞山1号墳CC BY-SA 4.0
Hodoyama Kofun Group is a megalithic mound (tumulus with integral stones) in Japan. A typological estimate: 250 CE to 650 CE. No English Wikipedia article exists for it; the full text below is the Japanese article "宝洞山1号墳", shown in the original language.
概要Sources for this section
- Wikipedia (Japanese): 宝洞山1号墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 宝洞山1号墳CC BY-SA 4.0
愛媛県東部、宇摩平野北東縁に位置する宝洞山の裾部に築造された古墳である。一帯では2号墳（ほぼ埋没）・3号墳（ほぼ消滅）が分布し、3基で宝洞山古墳群を構成する。これまでに発掘調査は実施されていない。
墳形は円形で、直径20メートル・高さ5メートルを測る。墳丘の北側には周溝を巡らすことで丘陵斜面をカットする。埋葬施設は両袖式の横穴式石室で、南方向に開口する。巨石が使用された石室であり、宇摩向山古墳（四国中央市金生町下分）・朝日山古墳（四国中央市金田町金川）との類似が指摘される。副葬品は詳らかでない。築造時期は古墳時代終末期の7世紀代と推定される。
古墳域は1976年（昭和51年）に四国中央市指定史跡に指定されている。
埋葬施設Sources for this section
- Wikipedia (Japanese): 宝洞山1号墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 宝洞山1号墳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いる。石室の規模は次の通り。
玄室：長さ4.1メートル、幅1.8メートル、高さ1.9メートル
羨道：長さ4.4メートル、幅1.3メートル、高さ1.5メートル
石室の形態は宇摩向山古墳（四国中央市金生町下分）と似る。また朝日山古墳（四国中央市金田町金川）に似た玄門柱石を伴う。
文化財Sources for this section
- Wikipedia (Japanese): 宝洞山1号墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 宝洞山1号墳CC BY-SA 4.0
四国中央市指定文化財
史跡
宝洞山一号墳 - 1976年（昭和51年）8月28日指定。
参考文献Sources for this section
- Wikipedia (Japanese): 宝洞山1号墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 宝洞山1号墳CC BY-SA 4.0
史跡説明板（川之江市教育委員会設置）
「天生津古墳」『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): 宝洞山1号墳CC BY-SA 4.0
Sources for this section
- Wikipedia (Japanese): 宝洞山1号墳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 “宝洞山1号墳”, 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
7 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
- 34°00′34″ N, 133°35′03″ EFor a GPS or map app: 34.00939, 133.58422
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 Q104660485wikidata.org
- 02Source for this dateen.wikipedia.org
Image files
- Hodoyama Kofun Group-1, entrance-2.jpgSaigen JiroCC0
- Hodoyama Kofun Group-1, funkyu.jpgSaigen JiroCC0
- Hodoyama Kofun Group-1, genshitsu-1.jpgSaigen JiroCC0
- Hodoyama Kofun Group-1, genshitsu-2.jpgSaigen JiroCC0
- Hodoyama Kofun Group-1, sendou-1.jpgSaigen JiroCC0
- Hodoyama Kofun Group-1, sendou-2.jpgSaigen JiroCC0
- Hodoyama Kofun Group-1, entrance-1.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 "宝洞山1号墳" (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): 宝洞山1号墳CC BY-SA 4.0
- Wikidata Q104660485CC0