Mitokusan Nageiredo: Visiting Japans Most Dangerous National Treasure Built in a Sheer Cliff Cave

Mitokusan in Misasa Town, Tohaku District, Tottori Prefecture is a mountain long revered as a sacred shugendo training site. Nageiredo (Thrown-In Hall), known as its inner sanctuary, is a National Treasure building set in a sheer cliff cave, known as Japans most dangerous National Treasure. It stands as if floating in a cave formed where erosion cut into the boundary between a tuff breccia layer and andesite, a figure without parallel.

The Mystery and Legend of Nageiredo

Dendrochronological analysis of its timbers confirms that Nageiredo dates to the late Heian period, and how it was constructed in this cliff cave remains a mystery today. According to legend, in the year 706 En no Ozuno, founder of shugendo, opened this mountain and threw the hall into the cliff with magical power. Zao Gongen is enshrined inside.

The Path to Pilgrimage: A Rigorous Mountain Trail

Pilgrimage to Nageiredo involves serious mountain climbing over rugged rocky terrain and tree-root paths. An offering and a climbing pilgrimage fee are required, and because difficult sections require gripping chains, mountain shoes without metal fittings are recommended. Sneakers may not be permitted, in which case entry can sometimes be allowed after changing into straw sandals (waraji) rented for a fee. The route is steep enough that fatal falls have occurred in the past, but the difficulty makes reaching the destination all the more moving.

Mitokusans Nature and Faith

The entire Mitokusan is developed as a shugendo sacred site, and pilgrims proceed inward while visiting multiple halls including Monju-do, Jizo-do, Kannon-do, and the bell tower. Monju-do and Jizo-do are said to date to the late Muromachi period and Kannon-do to the early Edo period. The approach through primeval beech and cypress forests has a mysterious atmosphere.

Together with Misasa Onsen

At the foot of Mitokusan wells up Misasa Onsen, one of the worlds foremost radium hot springs. It is ideal for soothing a body tired from the Nageiredo pilgrimage, and a two-day, one-night plan combining the two is a classic itinerary.

Practical Travel Notes

• Registration for the climbing pilgrimage is roughly from 8:00 to 15:00 (descent by around 16:30), so entry is not possible late in the day
• For safety, solo entry is not allowed and a group of two or more is mandatory
• Light clothing that leaves both hands free is essential, and entry is prohibited in rainy weather as it is dangerous
• In a typical year the mountain is closed to entry through the snowy period from around December to March, reopening on a set day in spring
• Since a climbing pilgrimage fee applies in addition to the offering, it is reassuring to bring cash for payment on site

Access

From JR Kurayoshi Station, 25 minutes by Nikko Bus to Misasa Onsen, then about 20 minutes by local bus to Mitokusan.

📚 Sources

This article draws on official information from Sanbutsuji temple on Mount Mitoku, guidance from the Misasa tourism association, and published cultural-property materials on the national-treasure Nageiredo hall. On-site notices at the mountain entrance were also consulted. Fees, reception hours, and dress requirements may change, so please confirm official information before your visit.

Visitor Checklist

• Estimated time: Allow roughly two to three hours for the round-trip climb to Nageiredo.
• Clothing and gear: Non-slip hiking shoes and easy-to-move clothing are essential for the cliff-side ascent.
• Entry preparation: Your attire is checked at the climbing reception, and entry is refused if requirements are not met.
• Getting around: Nageiredo can also be viewed from the worship point at the base, an option for those unsure of their stamina.
• Note: Solo entry is not permitted; climbers must proceed in groups of two or more.