Guida
Funatsu Tainai Jukei is a precious geological formation located in Fujikawaguchiko Town, Minamitsuru District, Yamanashi Prefecture, and is officially designated as a National Natural Monument of Japan. This site consists of unique lava tree molds created when molten rock from Mount Fuji's eruptions flowed around surrounding trees. As the trees eventually decayed, the hardened lava left behind hollow, sculptural cavities. With a total length of approximately 20 meters, these formations possess immense geological value and represent a breathtaking masterpiece of natural design. It is a rare spot where visitors can witness the raw power of nature firsthand.
This location is more than just a geological site; it is deeply intertwined with the spiritual traditions surrounding Mount Fuji. The eruptions that formed these structures are a testament to the immense power of the volcano throughout history. Furthermore, the interior of these hollow structures is associated with the worship of Konohanasakuya-hime, the deity of Mount Fuji. This connection highlights the site's role in the ancient reverence for nature and its recognition as part of the cultural landscape of the 'Mount Fuji, sacred place and source of artistic inspiration' (a UNESCO World Heritage-related site).
The most striking feature is the structure of the hardened lava that perfectly mimics the shapes of the original trees. Because the trees were swallowed by the lava and subsequently decayed, a hollow, cave-like structure known as 'Tainai' (the womb) was created. The primary attraction is the 'Tainai Meguri' (trekking through the womb), where visitors can explore the interior of these cavities. Navigating this fusion of nature and history within a confined, unique space offers an experience that cannot be found anywhere else.
As an outdoor natural site, the scenery changes beautifully with the seasons. Visiting during different times of the year allows you to experience the changing vegetation and the majestic backdrop of Mount Fuji, deepening your appreciation for the natural evolution of the landscape. The site is generally open from 9:00 AM to 5:00 PM. We recommend visiting during daylight hours to clearly observe the intricate textures and structures of the lava. Please note that visits are subject to weather conditions and geological safety assessments.
Visitors can experience a physical journey through the 'Tainai'—the hollowed-out sections of the lava. Walking through these natural, cave-like spaces provides a tactile understanding of geological processes. This activity goes beyond simple sightseeing, offering a direct connection to the history of the Earth and the volcanic traces left by Mount Fuji. Please note that exploration is conducted within safe, designated boundaries.
The area around Lake Kawaguchiko is rich with diverse attractions. Nearby spots include the Kawaguchiko Museum of Art, the Kawaguchiko Herb Hall, and Oishi Park, where you can enjoy a blend of nature, art, and local cuisine. Being at the foot of Mount Fuji, the area is perfect for strolls with stunning mountain views and exploring traditional crafts such as Oishi Tsumugi silk. You can easily plan a diverse sightseeing route utilizing the natural beauty of Fujikawaguchiko.
Cash may be required for entrance fees or nearby facilities. Please check local signage or current information regarding the acceptance of credit cards or IC cards.
While some signage may be available in English, most information and guidance are primarily in Japanese. It is recommended to research the site in advance if you require detailed information.
Generally, no prior reservation is required to visit, but please check the local operating status before your trip.
Because the terrain inside the 'Tainai' can be uneven and unstable, please wear comfortable, non-slip footwear such as sneakers or trekking shoes. Dress appropriately for the season and the outdoor environment.
Photography of the natural landscape is permitted; however, please strictly follow any local instructions regarding restricted areas or prohibited photography.
Due to the natural terrain, the site features many steps and uneven surfaces. It is not suitable for wheelchair users and has limited accessibility.
As a National Natural Monument, it is strictly forbidden to damage or remove any part of the lava structures. Please act with respect to preserve this historical and natural treasure.