Aokigahara — Sea of Trees
Aokigahara, also known as the Sea of Trees (Jukai), is a dense primeval forest covering approximately 30 square kilometres on the northwestern flank of Mount Fuji on the island of Honshu, Japan. The forest grows on a bed of hardened lava deposited by Mount Fuji’s last major eruption in 864 CE, which gives the ground a porous, sound-absorbing quality and creates a striking stillness within the trees. Aokigahara is both a popular tourist destination for its geological caves and dramatic scenery, and a site of deep cultural and contemplative resonance in Japanese tradition.
At a glance
- Type
- Ancient forest; natural heritage site; part of Fuji-Hakone-Izu National Park
- Period
- Forest established on lava flow of 864 CE eruption; continuous natural history
- Style
- Temperate mixed forest of Japanese cypress, oak, and other species growing over lava
- Location
- Northwestern flank of Mount Fuji, Yamanashi Prefecture, Honshu, Japan
- Coordinates
- 35.4773° N, 138.6581° E
Overview
Aokigahara lies at the base of Mount Fuji within Fuji-Hakone-Izu National Park and covers roughly 30 km² of terrain formed by the Jogan eruption of 864 CE. The porous lava rock beneath the forest floor absorbs sound and interferes with compasses and GPS signals, contributing to a pronounced sense of isolation that has shaped the forest’s reputation for centuries. The western edge of the forest, where several caves fill with ice in winter, draws large numbers of tourists and school groups each year.
History
The lava field on which Aokigahara stands was produced by the Jogan eruption of Mount Fuji in 864 CE, one of the mountain’s largest historical eruptions, which covered the area between two ancient lakes and created the current landscape. Over the following centuries forest succession established the dense mixed woodland visitors encounter today. In Japanese literary tradition the forest appears in works such as Seicho Matsumoto’s 1960 novel “Nami no To” (Tower of Waves), which contributed to its association with solitude and mortality. The forest is also referenced in the Ainu traditions of the region as a place of spiritual significance.
What you see
Visitors approach via well-marked tourist trails from the Aokigahara car parks near Lake Saiko (Saiko) and Lake Shoji. The Narusawa Ice Cave (Narusawa Hyoketsu) and Fugaku Wind Cave (Fugaku Fuketsu) are the principal geological attractions — both are lava tubes open to guided visits, with interiors that remain near freezing year-round. The tree canopy in the forest interior is so dense that the forest floor receives very little direct light, and the gnarled root systems growing over bare lava give the landscape an otherworldly appearance. Informational signage and emergency contact boards are placed throughout the trail network.
Cultural significance
Aokigahara holds a complex place in Japanese culture, understood simultaneously as a place of natural beauty, geological wonder, and deep contemplative quiet. The forest is a recognised component of the Mount Fuji World Heritage Site buffer zone and contributes to the broader cultural landscape that earned Mount Fuji UNESCO inscription in 2013. Local authorities and NPOs conduct regular awareness campaigns emphasising the forest’s natural and spiritual value.
Practical information
The forest is freely accessible year-round. The Narusawa Ice Cave and Fugaku Wind Cave charge a small entry fee and operate seasonally — check official websites for current hours. Guided nature tours depart from the Fugaku Wind Cave area. Visitors are strongly advised to stay on marked trails; the interior of the forest is extremely easy to become disoriented in. Mobile signal is limited in the forest interior.
Getting there
From Tokyo, take the Chuo Line to Otsuki, then the Fujikyuko Line to Kawaguchiko Station (approximately 2 hours). From Kawaguchiko, the Retro Bus or Saiko Bat Bus services stop at the cave entrances near Aokigahara. By car, the forest is accessed from Route 139 along the western shore of the Fuji Five Lakes region.