We’d written recently about Shimabara, on the Nagasaki peninsula just across Ariake Sea. Below is an addendum. In 1792, there was an event that became known as 島原大変肥後迷惑 (Shimabara taihen, Higo meiwaku, which translates as “Terrible day for Shimabara; an annoyance for Higo” - an understatement). Google it for interesting photos: it sculpted the geology that remains to this day. In a nutshell, volcanic activity on Mt Unzen created a massive protuberance which broke loose, resulting in a landslide falling into Ariake Sea. This unleashed a tsunami in the bowl-shaped sea which washed several kilometers across the Higo lowlands and then bounced back to Shimabara, making what was already a bad day there much worse. I had to take a laboratory science class in college so chose geology (“rocks for jocks”) as it was the easiest, but it spawned a lifelong interest in the topic. Often in Kumamoto you’ll come across a geological feature that doesn’t seem to belong. That event in 1792 answers many questions about the unique features to be found on the Shimabara peninsula. Unzen is currently dormant, but its potential to resume activity remains very high. It makes for a fascinating visit. - William https://ja.wikipedia.org/wiki/%E5%B3%B6%E5%8E%9F%E5%A4%A7%E5%A4%89%E8%82%A5%E5%BE%8C%E8%BF%B7%E6%83%91