A 350-Year-Old Tree on the Edge of Its World
On a steep cliff on the northern flank of Ishigakiyama, a single tree has held its footing for roughly three and a half centuries. It is a bakuchinoki, an evergreen member of the cherry and plum family, and where its trunk meets the slope it measures close to six meters around. On 9 December 1924 it was designated a national natural monument. Very few living things in Kanagawa Prefecture carry that status, and this tree was among the first.
The Japanese register the property as Hayakawa no Biranju. Hayakawa is the district of Odawara where it grows; biranju is a regional name for the species. The tree stands about 300 meters from the entrance to the Hakone Turnpike, on a sharp incline above a small hollow, roughly midway between the ruins of Odawara Castle and the hilltop site of Ishigakiyama Castle.
It is not a tree you stumble upon. The final stretch climbs a slope and a flight of stairs, and the tree reveals itself only at the top, rising some 20 meters with five heavy limbs branching from a short, thick base. Its crown reaches about 17 meters east to west and 14 meters north to south.
Why a Tree Becomes a National Treasure
Japan protects more than buildings and artworks. Outstanding natural features such as old trees, distinctive geology, and rare habitats can also be designated as natural monuments under the same legal framework. The bakuchinoki of Hayakawa was listed under the criterion covering notable trees, giant trees, and ancient specimens.
The reason lies in geography as much as in size. Bakuchinoki (Prunus zippeliana) is a species of the warm-temperate south. It is common in the milder parts of Shikoku and Kyushu, but in eastern Japan it grows only sparsely. Odawara sits close to the northeastern limit of its natural range, and a specimen of this scale, this far from the species' heartland, is genuinely unusual.
Among recorded bakuchinoki in Japan, the Hayakawa tree is exceptional for the girth of its trunk, and it remains the only individual of its species protected at the national level. When botanists surveyed it in the 1920s, they measured a trunk circumference of about one jō seven shaku in the units of the day, close to five meters, and noted the five great branches that still define its shape today.
The Gambler's Tree and Its Restless Bark
The standard Japanese name, bakuchinoki, translates literally as "the gambler's tree." The image behind it is blunt. The bark is grey-brown and, as the tree grows, it lifts away in scaly plates and falls off on its own. What remains exposed beneath is a warm reddish-yellow surface. To earlier observers, a trunk shedding its outer layer recalled a gambler stripped of his clothes after a losing run.
The alternative name, biranju, has a stranger history. It appears to come from biranju, a tree named in Buddhist scripture as a wind that blows at the beginning and end of the world. The two were confused long ago, and the mistaken name stuck, and stuck so firmly that it shaped the local landscape.
That last point is easy to miss. The patch of Hayakawa where the tree grows is officially named Biranji. The place took its name from the tree, not the other way around. A living thing gave its name to the ground it stands on, and the name has outlasted generations of people who knew it.
Three Centuries of Local Memory
Estimates of the tree's age differ from source to source, ranging from about 250 years to roughly 350. The figure cited most often by Odawara City is around 350 years, which places its early life in the Edo period.
Local accounts connect the tree to Ōkubo Tadazane, lord of the Odawara domain during the Bunka era of the early nineteenth century. The details are handed down rather than documented, but they suggest the bakuchinoki was already regarded as a remarkable tree in his day. A tree noticed and remembered for more than two centuries before its formal designation is a quiet measure of how long it has belonged to this hillside.
Visiting the Tree
The site is open ground, free to visit, with no gate and no fixed hours. Two railway stations sit within reach: Hakone-Itabashi Station on the Hakone Tozan Line, and Hayakawa Station on the JR Tōkaidō Line. Either gives a walk of about 20 minutes.
The walk itself is straightforward until the end. Odawara City has signposted the route in stages, and the tree is marked on standard mapping services. The difficulty is concentrated in the final approach, which climbs a steep, sometimes slippery slope and a set of stairs. Sturdy shoes are sensible, and wet weather makes the footing harder. Because the tree grows on a cliff face, it cannot be circled freely; the best views come from the approach and the small clearing at the top.
Spring is a pleasant time to make the trip, when early cherry blossom appears along the way to the nearby coast. The trunk's coloured bark, however, reads clearly in any season.
What Lies Nearby
The tree sits within easy reach of two of the area's major historic sites. The ruins of Ishigakiyama Castle, on the hill above, were raised by Toyotomi Hideyoshi during his 1590 campaign against the Hōjō clan, who then held Odawara Castle. Walking between the two, with the bakuchinoki between them, traces a line through one of the decisive moments in the unification of Japan.
Down the slope, Hayakawa is a working fishing port, and its harbour market is a good stop for a meal of the day's catch. Odawara Castle, fully reconstructed and surrounded by parkland, lies a short train ride away. The Hakone Turnpike, beginning close to the tree, climbs toward the hot-spring resorts and viewpoints of the Hakone highlands.
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Questions and Answers
- What kind of tree is this?
- It is a bakuchinoki (Prunus zippeliana), an evergreen tree in the same broad family as cherries and plums. The Japanese name means "gambler's tree," after the way its bark peels off in patches.
- Why was it designated a national natural monument?
- The species grows mainly in warm western Japan and is scarce in the east. Odawara sits near the northeastern limit of its natural range, and a tree of this size in such a location is botanically valuable. It is also the only bakuchinoki in Japan protected at the national level.
- How old is the tree?
- Estimates vary. Different surveys give figures between roughly 250 and 350 years; Odawara City most often cites about 350 years.
- Is it difficult to reach?
- The route is signposted and the tree is on standard maps, but the final approach climbs a steep, slippery slope and a flight of stairs. Wear sturdy shoes and take care, especially in wet weather.
- Are there opening hours or an admission fee?
- No. The tree stands on open hillside and can be visited freely at no charge. There are no facilities on site, so daylight hours are best.
Basic Information
| Name | Hayakawa no Biranju |
|---|---|
| Designation | National Natural Monument (designated 9 December 1924) |
| Location | 1374-1 Biranji, Hayakawa, Odawara City, Kanagawa Prefecture |
| Species | Bakuchinoki (Prunus zippeliana), family Rosaceae |
| Count | One tree |
| Dimensions | Height approx. 20 m; trunk girth at eye level approx. 4.9 m; girth at base approx. 6 m; crown spread approx. 17 m (E–W) and 14 m (N–S) |
| Estimated age | Approximately 350 years |
| Managing body | Odawara City (since 13 August 1925) |
| Access | About 20 minutes on foot from Hakone-Itabashi Station (Hakone Tozan Line) or Hayakawa Station (JR Tōkaidō Line) |
| Admission | Free; outdoor site, viewable at any time |
References
- National Database of Designated Cultural Properties, Agency for Cultural Affairs — Hayakawa no Biranju
- https://kunishitei.bunka.go.jp/bsys/maindetails/401/775
- Cultural Heritage Online, Agency for Cultural Affairs — Hayakawa no Biranju
- https://bunka.nii.ac.jp/heritages/detail/138257
- Odawara City — Natural Monument: Hayakawa no Biranju
- https://www.city.odawara.kanagawa.jp/field/lifelong/property/cultural/natural/tenbi.html
Last verified: 2026.05.25