Look up at the reddish-brown lava dome that emerged from a wheat field in just two years
About this spot
A lava dome created by the uplift of a peaceful wheat field during volcanic activity that continued for two years from 1943 (Showa 18). Designated as a Special Natural Monument of Japan as a rare "mountain born from a wheat field" worldwide, thin volcanic vapors still rise from its reddish-brown rocky surface. Sankoku Mimatsu, the postmaster of Sobetsu Post Office at the time, meticulously sketched the mountain's growth in his observational record "Mimatsu Diagram," which contributed to global volcanology, and there is a famous anecdote about him investing his personal fortune to purchase this mountain. At the base stand the Sankoku Mimatsu Memorial Hall conveying his achievements and souvenir shops. When grandchildren learn that this mountain was formed during their grandparents' childhood, the volcano becomes something tangible to them—a unique living geology lesson offered only by Toyako Lake.
Tips
About 15 minutes by car from Toyako Hot Spring Town. By parking at the fee-paying parking lot at the base, you can walk and combine the bear farm and Usui Mountain Ropeway, making it efficient to cover all three afternoon spots with this location as a base. The mountain is private land and a Special Natural Monument, so entry is prohibited; viewing is only from the base. For more detailed information about how the mountain was formed, visit the Sankoku Mimatsu Memorial Hall (separate admission fee).
Best time to visit
Approximately 30-45 minutes. Afternoon light illuminates the mountain slopes, showing the reddish-brown dome vividly in photos.
Access & map
Showa Shinzan, Sobetsu Town, Abuta District, Hokkaido 052-0102 (〒052-0102 北海道有珠郡壮瞥町昭和新山)
Model course featuring this spot

Toyako Lake Pleasure Cruise and Usui Mountain Ropeway - A Tour of Lake and Volcano
Hokkaido
Explore features & model courses
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