A Warm-Climate Grove on a Cool Hillside
Climb the slope on the north side of Yugawara Station and you reach a compact patch of evergreen woodland, only about 620 square meters, wrapped around a small wooden shrine to the mountain god. This is Yamagami no Jusō, the grove of the mountain god, which Japan listed as a national Natural Monument on 7 September 1939. The listing singled out one tree above all the others: a horutonoki (Elaeocarpus sylvestris) whose trunk measured roughly 5.5 meters around at chest height.
Walk the path today and you will not find that tree. The old giant died and was cut back to a stump, and a few younger trees have grown up in its place. That absence is part of what makes the spot worth understanding rather than a reason to skip it. The grove survives as a fragment of the warm-temperate evergreen forest that once covered more of this coast, and it holds the westernmost stand of evergreen broadleaf woodland left in Kanagawa Prefecture.
What a "Natural Monument" Protects Here
Japan's Natural Monument system, run by the Agency for Cultural Affairs, protects living things and landforms of scientific or cultural value in the same way the country protects temples and paintings. The category that covers Yamagami no Jusō is the one for notable trees, ancient trees, and sacred groves. What earned the designation in 1939 was not a single rare plant but a community of them growing together where, on the face of it, they should struggle.
Yugawara sits near the northern edge of the range for several southern, warm-loving species, and the grove is often described locally as marking a northern limit for the horutonoki. The tree takes its odd name from the 18th-century scholar Hiraga Gennai, who is said to have mistaken it for the Mediterranean olive that yields "Porto oil," the Portuguese oil of his day. Its small fruit does look like an olive, though it is not edible. Alongside the original giant, the 1939 record listed himeyuzuriha (Daphniphyllum teijsmannii), tabunoki (Machilus thunbergii), and yabunikkei (Japanese cinnamon, Cinnamomum yabunikkei).
The mix you see now reflects how the wood has changed. Camphor, tabunoki, yabunikkei, the yew plum pine inumaki, Japanese zelkova, and the fast-growing karasuzanshō all crowd the small slope, shading the shrine and the path that climbs to it.
A Shrine, a Warrior, and a Forest That Grew Itself
An information board at the entrance traces the grove back to the late 12th century. During the Jishō era, between 1177 and 1181, the local lord Doi Sanehira is said to have lived in this part of Yugawara, and a small shrine to the mountain god was enshrined here. The forest, by this account, simply grew up around the shrine on its own and was never planted.
Doi Sanehira is a real and well-documented figure. He was one of the seven riders who escaped with Minamoto no Yoritomo after the future shogun's defeat at the Battle of Ishibashiyama in 1180, and he went on to support the Minamoto cause as it rose to power. His name still anchors the local landscape, from the castle ruins above the town to the family temple below the grove. Whether or not the wood is quite as old as the legend claims, the link gives the place a human story to set beside its botany.
What to Look For on a Visit
This is a quiet, working piece of woodland rather than a polished attraction. The reward is atmosphere: a dim, close canopy that drops the temperature a few degrees, the small shrine sitting where the path levels out, and sudden gaps in the trees that frame the rooftops of Yugawara below. Stop on the way up and look at the trunks. The evergreen leaves overhead stay glossy through winter, which is the clearest sign that you are standing in a southern forest that has held on far north of where it belongs.
The grove is small enough to take in within a few minutes, so it pairs well with the temple and castle sites nearby rather than filling a day on its own.
Getting There and Nearby Sights
The grove lies a short way north of Yugawara Station, on the Tōkaidō Line. Reaching it means passing through the narrow Jōgan-ji underpass beneath the railway and then climbing a steep, easily missed footpath, so sturdy shoes help and the underpass is worth crossing with care, as cars use it too.
The natural partner to a visit is Jōgan-ji, the Sōtō Zen temple about ten minutes' walk from the station. Its great byakushin (Chinese juniper), reckoned to be around 800 years old and some 20 meters tall, is itself a national Natural Monument and the largest of its kind in Kanagawa; tradition holds that Doi Sanehira planted it. The temple grounds also hold the Doi family graves, a prefecturally designated historic site, and the Shichiki-dō hall dedicated to Yoritomo's seven riders. From the temple a trail leads up to Shiroyama, where the remains of Doi Sanehira's castle look out over the Manazuru Peninsula and Sagami Bay. Down in the valley, the hot springs of Yugawara Onsen have drawn writers and travelers for well over a century.
- 📍 Plan Your Visit to Kanagawa
- Find tours, activities & transport passes near Mountain God's Grove
- [ Kamakura Buddha Hakone Onsen & Yokohama Tours ]
Q&A
- Can I still see the giant tree the grove is famous for?
- No. The large horutonoki that the 1939 listing was built around has died, and only younger trees remain. The grove is still protected as a surviving example of warm-temperate evergreen forest, which is what its value rests on today.
- Is it hard to find?
- It can be. The grove sits on a slope north of Yugawara Station, reached through a narrow railway underpass and up a small, steep path that is easy to walk past. Allow extra time and wear shoes with grip.
- Is there an entrance fee or set opening time?
- No. It is an open hillside grove with a small shrine and a footpath, free to enter at any time. As an active place of worship, it asks for the same quiet respect you would give any small shrine.
- How is the grove connected to Doi Sanehira?
- A local tradition, recorded on the site's information board, says the mountain-god shrine was enshrined here in the Jishō era (1177-1181), when Sanehira lived in the area, and that the forest grew up around it. Sanehira was a noted supporter of Minamoto no Yoritomo.
- What else is worth seeing close by?
- Jōgan-ji temple, with its ancient Chinese juniper and the Doi family graves, is the obvious pairing. The Doi castle ruins on Shiroyama and the baths of Yugawara Onsen round out a half-day in the area.
Basic Information
| Name | Yamagami no Jusō (Grove of the Mountain God) |
|---|---|
| Location | 331-333 Shirobori, Yugawara-machi, Ashigarashimo-gun, Kanagawa Prefecture |
| Designation | National Natural Monument (designated 7 September 1939) |
| Managing body | Yugawara Town (designated 26 August 1940) |
| Area | Approximately 620 square meters |
| Principal vegetation | Warm-temperate evergreen broadleaf grove: tabunoki, yabunikkei, camphor, inumaki, Japanese zelkova, karasuzanshō (the original large horutonoki has died) |
| Access | North of Yugawara Station (Tōkaidō Line), via the Jōgan-ji underpass and a steep footpath |
| Admission | Free; open grove with a small shrine, no set hours |
References
- Database of National Cultural Properties, Agency for Cultural Affairs (Yamagami no Jusō)
- https://kunishitei.bunka.go.jp/bsys/maindetails/401/796
- Cultural Heritage Online, Agency for Cultural Affairs (Yamagami no Jusō)
- https://bunka.nii.ac.jp/heritages/detail/138277
- Yugawara Town official site, Natural Monuments page
- https://www.town.yugawara.kanagawa.jp/kyoiku/rekishibunnka/natural-monument.html
- Jōgan-ji, Yugawara Onsen official tourism site
- https://www.yugawara.or.jp/sightseeing/746/
- Hakone Geopark, Jōgan-ji guide
- https://www.hakone-geopark.jp/area-guide/yugawara/038jyougannji.html
Last verified: 2026.05.28