Mt.ASAMA Magma Stone Park is a spectacular volcanic landscape formed by lava from the Great Tenmei Eruption of Mt. Asama in 1783, during the reign of Ieharu Tokugawa, the 10th shogun of the Edo period. Located within the Mt. Asama North Geopark, the park highlights the dramatic power and beauty of nature.

The Great Tenmei Eruption brought about two major disasters.
The first was a massive pyroclastic flow that swept up earth and water along its path, transforming into a deadly mudslide. It buried the village of Kanbara at incredible speed, then flowed into the Agatsuma River, merged with the Tone River, and eventually reached Edo—modern-day Tokyo. Along the way, it devastated riverside communities, affecting around 1,500 people, including 477 residents of Kanbara. Remarkably, 93 villagers who fled to Kanbara Kan-nondo Temple survived. Against the odds, they rebuilt their lives, and today, the village has recovered into a community of around 1,000 people.
The second disaster was caused by the volcanic ash and gases released during the eruption.
These particles rose all the way to the stratosphere and remained in the atmosphere, blocking sunlight even during the day. As a result, crops failed to grow, which greatly prolonged the Great Tenmei Famine and deepened the suffering across the region.

The lava at Mt.ASAMA Magma Stone Park is the result of the final flow from Mt. Asama’s crater, which cooled and solidified into the dramatic formations you see today.
According to old legends, demons were believed to inhabit Mt. Asama. When people witnessed this otherworldly landscape after the eruption, they said it looked as if demons had gone on a rampage and pushed out the rocks—hence the name “Onioshidashi Magma,” meaning “pushed out by demons.”

Mt.ASAMA Magma Stone Park offers stunning seasonal scenery throughout the year—alpine flowers in spring, refreshing cool air in summer, vibrant autumn foliage, and serene snow-covered landscapes in winter.
Within the park, you'll find the Asamayama Kannon-do, a branch temple of Toeizan Kan'ei-ji Temple in Tokyo, built to honor the lives lost in the eruption.
Pets are welcome too, so feel free to bring your furry companions along as you explore this breathtaking natural wonder.