Guide
Narusawa Lava Tree Formations (Narusawa Yogan Jukei) is a precious natural heritage site located in Narusawa Village, Yamanashi Prefecture, designated as a Special Natural Monument of Japan. The site features hollow cavities left behind after lava flows engulfed a forest, causing the trees to burn away and leave empty shells. This unique landscape is a direct result of the dynamic volcanic activity of Mt. Fuji and is considered an extremely rare geological phenomenon.
The history of this site dates back to the Jogan eruption of 864 AD during the early Heian period. A massive eruption occurred on the northwest flank of Mt. Fuji, sending vast amounts of lava flowing through the surrounding forest. As the lava moved, the heat and gas caused the trees to burn out, leaving the distinctive hollow shapes of the trunks. This site was designated as a Natural Monument in 1929 and was later elevated to a "Special Natural Monument" in 1952 due to its immense academic and historical significance.
The most striking feature is the tree-shaped cavities within the lava. Specifically, the 11th formation was identified through research in 1993 as a "lava spicule" (lava steam vent), where moisture in the lava evaporated and created high gas pressure, leading to a small explosion. This is a world-class geological rarity. From the protected viewing areas, you can visually grasp the incredible process of how molten rock envelops and preserves the shape of life.
As an outdoor natural monument, the scenery changes with the seasons. From spring to summer, you can enjoy the contrast between the dark, textured lava and the lush green vegetation. In autumn, the surrounding foliage adds a beautiful layer of color to the rugged landscape. Visiting during bright daylight hours is recommended, as the sunlight clearly defines the textures and depth of the hollows, making it perfect for photography.
Visitors can observe the intricate shapes created by nature up close. Studying the silhouettes of the trees left in the lava and the traces of geological phenomena like lava spicules offers a profound way to learn about the history of Mt. Fuji's eruptions. The surrounding environment allows you to experience the volcanic topography of the Mt. Fuji foothills through all your senses.
The Narusawa Lava Tree Formations are easily accessible, located along Route 139 which connects Fujiyoshida City and Lake Motosu. The area is home to several other natural monuments related to Mt. Fuji's volcanic landscape, such as the Fugaku Wind Cave and Narusawa Ice Cave. Visiting these nearby spots will give you a deeper understanding of the diverse natural scenery shaped by volcanic activity.
Since you will be observing natural terrain, we recommend wearing comfortable walking shoes and casual clothing. As this is a protected natural area, please do not touch the protective barriers or chains. To help preserve the environment, please ensure you take all trash with you when you leave.