Hot springs in Unzen

A small hot spring town on the Shimabara Peninsula in Nagasaki Prefecture, set at the foot of Mount Unzen with views across the Shimabara Straits. The springs here are among the hottest in Japan, reaching 105 degrees Celsius. The famous 105-meter outdoor footbath on the seafront is the longest in Japan and open to all visitors free of charge.

A highland onsen in Unzen-Amakusa National Park at around 700 meters elevation. The dramatic sulfurous steam vents known as the Jigoku, or Hell Grounds, are the defining feature: they bubble, hiss, and release clouds of white vapor across the landscape. The water here is strongly acidic and celebrated for its skin-healing properties.