Chichibu ga Ura Park

Chichibu ga Ura Park sits on the edge of Shimabara's waterfront, shaped by the Shimabara Catastrophe of 1792. That event began with months of eruptions and earthquakes, culminating in the collapse of the Mt. Mayuyama lava dome into the Ariake Sea. More than 15,000 people were killed in the resulting landslide and tsunami. The mountain debris transformed the harbor and scattered new islands across the water. The park offers a place to understand this landscape: the uneven seafloor became a rich marine habitat, and the collapsed earth gave rise to fresh springs that locals use to this day.