Ono no Shidareguri Jiseichi: A Mystical Forest of Weeping Chestnut Trees in Nagano
Tucked away on a west-facing mountain slope in Tatsuno Town, Nagano Prefecture, lies one of Japan's most extraordinary natural wonders: the Ono no Shidareguri Jiseichi, a wild grove of "weeping chestnut" trees so peculiar that local villagers once believed it to be the dwelling place of tengu, the long-nosed mountain spirits of Japanese folklore. Over 800 chestnut trees with branches drooping like umbrellas spread across a 3.4-hectare slope at elevations between 950 and 1,200 meters, forming the largest natural grove of its kind in all of Japan. Designated as a National Natural Monument in 1920, this otherworldly forest offers visitors a rare glimpse into the strange beauty that nature, through a quiet act of mutation, can create.
What Are Shidareguri (Weeping Chestnut Trees)?
Shidareguri are a naturally occurring mutant variety of the Japanese chestnut tree (Castanea crenata), known locally as shibaguri. Unlike ordinary chestnut trees, whose branches reach skyward in straight, upright fashion, the shidareguri's branches twist and bend before cascading downward, creating a silhouette reminiscent of a giant green umbrella or a windswept bonsai magnified to forest scale. The trees owe their distinctive form to two simultaneous genetic traits: the "weeping" tendency of their side branches, and the unusual habit of their apical buds (the topmost growing tips) dying off after only a few years, allowing the side buds to take over growth direction. The resulting trees are gnarled, sprawling, and utterly unique—each one shaped by decades of competing growth impulses pulling skyward and earthward at once.
Genetic research conducted by Japan's National Agriculture and Food Research Organization has confirmed that the weeping trait at Ono is carried by a dominant gene, which explains how the grove has been able to regenerate naturally and sustain itself as a pure stand for centuries.
A Forest of Tengu: History and Legend
The grove's existence has been known since at least the Edo period. A 1753 geographical record of Shinano Province titled Chikuma no Masago contains a passage referring to the trees as "the weeping chestnuts of Tengu Forest in Minamiono Village, Ina District." For generations, the contorted, almost serpentine forms of the chestnut trees inspired both wonder and dread among locals, who avoided the area entirely, calling it Tengu no Mori—the Forest of the Tengu—and believing the trees themselves to be transformed by supernatural forces.
Two enduring local legends attempt to explain the strange shapes. One holds that the wandering Buddhist saint Kobo Daishi bent the branches downward so that villagers could more easily reach the chestnuts. The other tells of tengu using the trees as their personal larder, whose great weight as they perched on the branches caused them to droop forever after. Whatever one chooses to believe, this aura of mystery and superstition is itself part of why the grove has survived: villagers' reverent fear discouraged felling, and the trees were left undisturbed for centuries.
Why It Was Designated a National Natural Monument
Ono no Shidareguri Jiseichi was designated a National Natural Monument on July 17, 1920, originally under the name "Onomura Shidareguri Jiseichi" (Weeping Chestnut Habitat of Ono Village), and renamed to its current title in 1957. The designation recognizes the grove not as a single magnificent tree, but as a habitat of exceptional botanical importance.
Of the four known wild shidareguri habitats in Japan—located in Iwaki (Fukushima), Shiojiri and Tatsuno (Nagano), and Gero (Gifu)—only the Tatsuno and Gero sites are protected at the national level. Among these, Ono is the largest by a wide margin, with around 800 trees of varying ages forming a true pure stand. Approximately 200 individual trees exceed one meter in trunk circumference, and the largest specimens reach four meters around. The site is recognized as a phenomenon of extraordinary value to the study of plant teratology (the science of biological abnormalities) and natural genetic mutation.
In 1985, the local town of Tatsuno also designated the shidareguri as its official town tree, cementing its status as a beloved emblem of the region.
Highlights and Best Times to Visit
The grove is part of the larger Shidareguri Shinrin Koen (Weeping Chestnut Forest Park), which falls within the Enrei-Ojo Prefectural Natural Park established in 1964. While beautiful in every season, two periods are particularly recommended for visitors hoping to capture the grove's strangest and most photogenic moments.
Spring: The Awakening of New Buds
From late April through May, fresh green leaves begin to unfurl from the bare, twisting branches. Before the canopy fills out, the dramatic architecture of each tree remains visible, and the contrast between dark, gnarled trunks and the soft new growth is especially striking. Photographers favor this season for capturing both form and color simultaneously.
Winter: The Snow-Covered Spectacle
Winter snow transforms the grove into what locals call tenka no kikan—"a wonder beyond compare." The umbrella-shaped canopies catch falling snow and glaze the bare branches in white, producing a scene of such fragile, sculptural beauty that photographers travel from across Japan to witness it. Note that this view is only possible on days with fresh snowfall, and the road into the forest park is not cleared in winter, so access requires care and proper preparation.
The Great Trunk at the Center
Near the center of the accessible viewing area stands the grove's largest tree—a colossal specimen with a trunk circumference of approximately four meters. Although now deceased, its three-pronged form continues to dominate the surrounding landscape, its skeletal silhouette spreading outward like frozen lightning. Even in death, this tree remains one of the most powerful and frequently photographed features of the grove.
Surrounding Attractions
The Tatsuno area offers several worthwhile destinations to combine with a visit to the shidareguri grove:
- Shidareguri Shinrin Koen (Weeping Chestnut Forest Park): The park surrounding the grove includes campgrounds, walking trails, and viewing areas managed by Tatsuno Town.
- Enrei-Ojo Prefectural Natural Park: A larger natural park offering panoramic views over Lake Suwa and the surrounding mountains.
- Ono-juku: A historic post town along the early route of the Nakasendo (one of the great Edo-period highways), preserving traces of the area's role as a transit point between the Suwa Basin and the Kiso Valley.
- Hotaru Park (Matsuo Kyo): Famous for its summer firefly displays in mid-June, when tens of thousands of fireflies illuminate the valley.
- Suwa Taisha Shrines: One of Japan's oldest and most revered Shinto shrine complexes, located approximately 30 minutes away.
- 📍 Plan Your Visit to Nagano
- Find tours, activities & transport passes near Ono's Weeping Chestnut Grove
- [ Matsumoto Castle & Kamikochi Hiking Tours ]
Q&A
- When is the best time of year to visit Ono no Shidareguri Jiseichi?
- Spring (late April to May), when fresh leaves unfurl against the dark, gnarled branches, and winter (after fresh snowfall), when the umbrella-shaped canopies are blanketed in white, are the two most spectacular periods. Note that the access road is not cleared in winter, so prepare accordingly.
- How do I get to the grove from Tokyo or Nagoya?
- By car, take the Chuo Expressway and exit at either Iho IC or Shiojiri IC; both are about 20 minutes' drive from the site. By train, ride the JR Chuo Main Line to Ono Station, then take a taxi for approximately 5 minutes. Note that the Enrei-Ojo Park Line road from the Okaya City side is closed in winter.
- Why do the trees look so unusual?
- The trees owe their distinctive shape to a natural genetic mutation that combines two traits: branches that "weep" or bend downward, and apical buds that die after a few years, transferring growth to the side buds. Over decades, these competing forces produce the contorted, umbrella-like forms seen today.
- Are there other shidareguri groves in Japan?
- Yes, four wild groves are known: in Iwaki (Fukushima), Shiojiri and Tatsuno (Nagano), and Gero (Gifu). Of these, only Tatsuno's Ono grove and Gero's Takehara grove are designated as National Natural Monuments. Ono is by far the largest, with around 800 trees.
- Is there an admission fee or visiting hours?
- There is no admission fee, and the grove can be visited freely as part of the surrounding Shidareguri Shinrin Koen. Restrooms and parking are available at the park, but facilities may be limited outside the main visitor seasons.
Basic Information
| Name | Ono no Shidareguri Jiseichi (Habitat of the Ono Weeping Chestnuts) |
|---|---|
| Designation | National Natural Monument (designated July 17, 1920) |
| Location | Ono, Nirezawa, Tatsuno-machi, Kamiina-gun, Nagano Prefecture (within Shidareguri Shinrin Koen) |
| Area | Approximately 3.4 hectares |
| Elevation | 950–1,200 meters |
| Number of Trees | Approximately 800 (around 200 with trunk circumference exceeding 1 meter; largest approximately 4 meters) |
| Species | Castanea crenata var. pendula (a mutant variety of the Japanese chestnut) |
| Managing Body | Tatsuno Town |
| Access | 20 minutes by car from Iho IC or Shiojiri IC on the Chuo Expressway; 5 minutes by taxi from JR Chuo Main Line Ono Station |
| Admission | Free |
| Inquiries | Tatsuno Town Tourism Association (Industry Promotion Division), Tel: 0266-41-1111 |
References
- Ono no Shidareguri Jiseichi - Cultural Heritage Online (Agency for Cultural Affairs)
- https://bunka.nii.ac.jp/heritages/detail/216429
- Ono no Shidareguri Jiseichi - Tatsuno Town Official Website
- https://www.town.tatsuno.lg.jp/gyosei/soshiki/sangyoshinkoka/kankosite/4/4/1231.html
- Ono no Shidareguri Jiseichi / Tatsuno Town Official Website (Enrei-Ojo Prefectural Park)
- https://www.town.tatsuno.lg.jp/kanko/miru_asobu/enreiojokenritsukoen/2037.html
- Ono no Shidareguri Jiseichi - Wikipedia
- https://ja.wikipedia.org/wiki/小野のシダレグリ自生地
- Ono no Shidareguri Jiseichi - Shinshu Silk Road
- https://shinshu-silkroad.jp/小野のシダレグリ自生地/
Last verified: 2026.05.05