About & Editorial Policy
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The Kofun Explorer Map (kofun-map.com) is a free site for exploring kofun in the Kansai (Kinki) region and imperial mausolea across Japan, on an interactive map and on individual guide pages. For each kofun we summarize its shape, size, date and designations, and the views on who is buried there, with sources, in English and Japanese.
Our aim is to let visitors and researchers check, from public sources, where each kofun is and how much is actually known about it.
Operator
| Site | Kofun Explorer Map (https://kofun-map.com/) |
|---|---|
| Operator | MICHI Corporation (株式会社MICHI) |
| Address | 3-801 Nagasone-cho, Kita-ku, Sakai, Osaka 591-8025, Japan (〒591-8025 大阪府堺市北区長曽根町3番地 シュライククリエイティブセンター801号室) |
| Corporate number | 7120101068125 |
| Company website | https://michi-collective.com/ (Japanese) |
| Contact | contact@michi-collective.com (what to send us) |
Editorial policy
Official status and the archaeological view are kept apart
The Imperial Household Agency's designation and management of a tomb as an imperial mausoleum, and any national or local heritage designation, go under “Official status.” The date of construction, the structure of the mound and burial facility, and scholarly views on who is buried there go under “Archaeological view.” The two are shown side by side but separately, because for some tombs the occupant designated by the Imperial Household Agency differs from the one favored by researchers.
- Attribution (jitei) is the Imperial Household Agency's determination of whose tomb it manages. It is a separate system from heritage designation.
- Scholarly views are attributed to the local government or researcher who holds them.
- Under each name, the Imperial Household Agency's name for the mausoleum or tomb is labeled “Imperial Household Agency:” and other names are labeled “Also known as:”.
Source priority
We check information against public and primary sources in the following order. The sources for each kofun are listed at the end of its page.
- The Imperial Household Agency (designations, mausoleum names, visiting information)
- The Agency for Cultural Affairs and official World Heritage materials (historic-site designations, World Heritage components)
- Prefectural and municipal governments and boards of education (shape, size, location, present condition)
- The Nara National Research Institute for Cultural Properties, excavation reports and other scholarly sources
- Wikipedia, Wikidata and similar sources (used for cross-checking and alternative names, and backed up by primary sources)
What cannot be confirmed is not stated
- A new entry is listed only when its shape, size, location and designation can be confirmed by two or more independent sources.
- Where sources disagree, both figures are given in the text. Figures that cannot be confirmed are omitted.
- The size field gives mound dimensions only. The dimensions of a mausoleum precinct (land managed by the Imperial Household Agency) are not given.
- “Last updated” on each kofun page is the date that kofun's data last changed.
Listing criteria — which kofun we include
This is a curated selection, not an attempt to cover all ~160,000 kofun nationwide. Centered on the seven prefectures of the Kansai (Kinki) region (Osaka, Nara, Kyoto, Hyogo, Shiga, Wakayama and Mie), a kofun is included if it meets any one of these six objective criteria.
- Components of the World Heritage sites "Mozu-Furuichi Kofun Group" (49) and "Asuka-Fujiwara" (7)
- Mausolea, reference sites and satellite tombs designated by the Imperial Household Agency (this category covers the whole country)
- Special Historic Sites, National Historic Sites and prefecture-designated historic sites
- Tombs whose excavated finds are designated cultural properties (National Treasure, Important Cultural Property or prefectural)
- Scale — keyhole-shaped, square-fronted square-backed or scallop-shaped mounds 80m or longer, or round/square mounds 50m or more across
- Large groups of roughly 100 or more extant mounds (shown as one marker at a landmark spot)
Kofun whose mounds no longer survive are included when academically important, clearly marked as “no longer extant.”
Why some imperial mausolea that are not kofun are listed
Criterion 2 (tombs designated by the Imperial Household Agency) covers every period and the whole country. As a result, the map also includes imperial mausolea that are not kofun: medieval mausolea, some in temple grounds; mausolea in the form of stone pagodas or halls; and modern mausolea with a round-on-square mound. The mausolea of all emperors from the 1st to the 124th are included, so imperial tombs can be followed on one map from the Kofun period to the modern era. This is why the site covers “kofun in Kansai and imperial mausolea nationwide.”
Coordinates & map
- Map pins are placed at the center of the mound (for lost mounds, the center of the former site; for kofun groups, a landmark spot).
- Coordinates come mainly from the Geospatial Information Authority of Japan (read from GSI maps and elevation data, or from its place-name search), Wikipedia and Wikidata, and OpenStreetMap (© OpenStreetMap contributors). Some kofun still have coordinates taken from Google Maps; we are replacing them with values from other sources.
- The base map is created by modifying GSI Tiles (pale map) from the Geospatial Information Authority of Japan (colors adjusted for display).
Corrections & contact
For corrections, press and interview requests, and inquiries from local governments, museums and research institutions, please email the operator's contact address. We accept messages in English or Japanese.
Contact address of the operator (MICHI Corporation)
contact@michi-collective.com
- When reporting an error, please include the name of the kofun (or the page URL) and a source that supports the correction (an Imperial Household Agency or local government page, a report, etc.). This speeds up checking. We correct entries after checking the sources.
- Supporter applications and questions about listings are also handled through our Supporter LINE account (in Japanese).
- Requests and complaints about personal information are handled as described in our privacy policy.
Supporters
The Kofun Explorer Map is free to use and is supported by individual and business supporters. Business supporters include businesses affiliated with the operator, MICHI Corporation. Whether or not someone is a supporter has no effect on which kofun are listed or what the pages say.
Related pages
- Development history (features and data added since launch)
- Privacy policy (English summary)
- Notice under the Specified Commercial Transactions Act (Japanese)
- Become a supporter (Japanese)