Showa-shinzan is Japans youngest mountain.
It appeared on 28 December 1943 out of a wheat field accompanied by strong tremors and hot lava.
Showa-shinzan erupted when Japan was fighting the Allies in the Second World War.
The authorities tried to hush it up and requested the locals to keep the mountain a secret.
But Masao Mimatsu, a postmaster living nearby began observing and recording the volcano’s progress.
Because of Japans war effort, basic scientific materials were unavailable and Mimatsu had to improvise.
Masao Mimatsu strung several fishing lines horizontally across two vertical beams at his post office.
Some say this happened when the volcano was still growing.
Others say he bought the land after the volcano stopped erupting.
Related:Paricutin, The Volcano That Grew Out Of A Cornfield
