Seicho-no-O-Sugi is a magnificent giant cedar tree growing within the grounds of Seicho-ji Temple in Kamogawa City, Chiba Prefecture. Its estimated age is variously said to be between 400 and more than 800 years, and it was designated a National Natural Monument in 1924.
It is the largest giant tree in Chiba Prefecture and is regarded as one of the most remarkable cedar trees in the Kanto region, alongside the Nakagawa Hoki Cedar in Kanagawa Prefecture. Locally, it has long been affectionately known as the “Millennium Cedar”.
The cedar reaches approximately 45 meters in height and has a trunk circumference of about 15 meters. As a single-trunk cedar, it is among the largest of its kind in Japan.
There is a hollow at the base of the eastern side of the trunk, which is used as a small shrine sanctuary. Despite the hollow and its immense age, the tree remains remarkably vigorous and continues to thrive.
There was once another cedar nearby that was almost the same size. However, it was blown down by a typhoon in 1954. During the same storm, the Seicho-no-O-Sugi also lost a large number of branches on its southern side.
Even after suffering this damage, the great cedar continued to grow. Its ability to survive and flourish over generations has inspired many visitors and made it one of the most recognizable symbols of Seicho-ji Temple.
Seicho-ji Temple is a major temple of Nichiren Buddhism located in Kiyosumi, Kamogawa City. It is famous as the sacred place where Nichiren is said to have entered the Buddhist priesthood and later proclaimed the establishment of his Buddhist teaching.
The temple is counted among the four sacred sites of Nichiren Buddhism and has a history dating back to 771, when a monk known as Fushigi Hoshi is said to have enshrined an image of Kokuzo Bosatsu, the Bodhisattva of Space and Wisdom.
Mount Kiyosumi is centered around Mount Myoken, which rises to approximately 377 meters. The entire temple area lies within the Minami Boso Quasi-National Park.
The mountain is notable for its diverse vegetation. The northern slopes support plants characteristic of a warm-temperate climate, while subtropical vegetation can be found on the southern slopes.
The grounds also include a research forest operated by the University of Tokyo’s Faculty of Agriculture, giving the area considerable academic as well as environmental value.
322-1 Kiyosumi, Kamogawa City, Chiba Prefecture, within the grounds of Seicho-ji Temple
Seicho-ji Temple is a special place where historic Buddhist buildings and the rich natural environment of Mount Kiyosumi come together. Above all, the overwhelming scale of Seicho-no-O-Sugi leaves a lasting impression on visitors.
Standing beneath this enormous cedar offers a chance to appreciate the passage of centuries and the remarkable resilience of living trees.
Visitors can take a peaceful walk around the temple grounds while exploring its historic buildings and sacred sites. At Asahigamori, visitors can also enjoy views of the sunrise while reflecting on the area’s long religious history.
Seicho-no-O-Sugi and Seicho-ji Temple are valuable destinations in Chiba where history, religion, architecture, and nature come together. The enormous cedar, known locally as the “Millennium Cedar,” has survived for centuries and stands as a powerful symbol of the temple and its surrounding natural environment.
By visiting the giant tree and exploring Seicho-ji, travelers can discover both the fascinating history of Nichiren Buddhism and the rich natural heritage of the Kiyosumi area. A visit offers a memorable opportunity to experience the enduring beauty of both Japan’s historic culture and its forests.