わたしたちの想い

Hachiro Cedar & Itsukushima

Itsukushima Shrine and Hachiro Cedar: Interactive Investigation

Was the Hachiro Sugi from Yoshiwa used in Itsukushima Shrine?

The investigation confirmed that Japanese Cedar (Sugi) was used in the Great Torii Gate of Itsukushima Shrine. However, direct historical records confirming it was the “Hachiro Sugi from Yoshiwa, Hatsukaichi City” have not been found. This does not mean it was not used. This report aims to deepen the understanding of the relationship between Itsukushima Shrine and the forestry history of the Yoshiwa area, promoting a greater appreciation for the local natural and cultural wealth.

Use this interactive application to explore the details of this mysterious connection. Examine the structure of the Great Torii, delve into the epic tale of the wood used, and uncover the legend of the Hachiro Cedar.

Exploring the Torii Structure

Click or tap on each part of the Torii to see the specific timber used. The explanation will appear below the Torii diagram.

Kasagi (Top Lintel)
Shimagi (Second Lintel)
Nuki (Tie Beam)
Main Pillar
Support Pillar
Daiwa (Base Ring)

Select a Part

The Story of Two Woods

Why are the main pillar’s origins documented, but the Japanese Cedar’s source remains a mystery?

Main Act: The Epic Journey of Camphorwood (Kusunoki)

The giant Camphorwood used for the Torii’s Main Pillars is exceptionally rare. During every reconstruction, extensive searches were conducted across Japan, and these efforts were meticulously recorded in detail.
Itsukushima
🌳 Miyazaki
🌳 Kagawa
🌳 Fukuoka
🌳 Saga
🌳 Wakayama

Supporting Role: The Mysterious Origin of Japanese Cedar (Sugi)

Conversely, Japanese Cedar used for the Support Pillars and other parts was considered easier to procure. While some records indicate procurement from Miyajima Island itself, other sources are unspecified. It was likely so common locally that detailed provenance records were deemed unnecessary.

Estimated Main Timber Composition
of the Great Torii

What is Hachiro Sugi?

So why is the “Hachiro Sugi” from Yoshiwa a candidate? It is because this Japanese Cedar possesses exceptionally excellent characteristics as a building material.

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Durability and Strength

Highly rated as a “powerful wood,” it boasts high strength. It is expected to withstand long-term exposure to salt air and moisture.

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Stability and Drying Resistance

Strong against drying, it shows stable performance with minimal internal cracking, even in large cross-sections. This resistance to warping makes it ideal for large-scale construction.

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Superior Growth Characteristics

Highly resistant to lack of sunlight, and less prone to producing flowers or cones. Its potential for long-term, sustained growth allows for utilization as monumental timber.

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Geographical Proximity

Located in a forestry region within the same Hatsukaichi City as Itsukushima Shrine. Historically, there has been a deep connection between the shrine and the supply of local timber.

These characteristics suggest a high possibility that local, high-quality timber was used in the shrine. However, the “smoking gun”—the official record—is yet to be found.

Future Outlook

Solving this mystery requires further investigation of ancient documents and scientific analysis of existing timber (such as dendrochronology). Future research may reveal new links connecting the Yoshiwa Japanese Cedar and Itsukushima Shrine.

© 2025 Interactive Investigation Report.