Showa Shinzan is a volcano located near Sobetsu-cho, Usu-gun, Hokkaido, and is part of the Shikotsu-Toya National Park. It towers 398 meters high, but is shrinking every year as a result of falling temperatures and erosion. It is a nationally designated natural monument.
There was visible volcanic activity 17 times during the two years from December 1943 through September 1945, which was during the Second World War, but the fact of the eruptions was kept from the public in order to suppress civil unrest. It was also impossible to conduct official surveys.
In order to thoroughly protect the volcano, which is precious even from a global perspective, and to support residents who lost their homes or farms, the local post master, Masao Mimatsu, purchased the land that the mountain had formed on.
Therefore, Showa Shinzan is located on the private land of the Mimatsu household, and is one of the few volcanoes in the world that is located on private land, similar to New Zealand’s White Island.
At the present time, the Masao Mimatsu Volcano Memorial Museum is located at the foot of Showa Shinzan, and the building displays various types of material, including Masao Mimatsu’s survey records.
Showa Shinzan (left) and Mount Usu (center)