Unzen Onsen, high in the peaks of the Shimabara peninsula, is one of Kyuushuu's nicest soaking spots. Views are incredible from some of the hotels, and the entire area is one of Japan's oldest national parks. There's hiking, birdwatching, boating, and of course, onsen hopping to do here. Many of the hotels offer higaeri (day use) visits, and the tourism board can recommend places to stay. If you're on a budget, don't overlook the public baths, which are inexpensive and just as good. The water's hot, odoriferous, and refreshing.
Unzen offers bathers a host of sulfurous options and some cool walkways through the jigoku (unbatheable 'hells'), where steam hisses up through cracks in the earth and pools of scalding mud blurp with the consistency of hot paint.
Unzen is best reached by car or bus, though a train does reach the Shimabara peninsula, with a terminus in Shimabara. The Shimabara peninsula is a bit remote, so plan on a long bus ride from Nagasaki City if you want to reach the onsen. Once there you'll have a bunch of spots to choose from, many of them fancy hotels with all the trimmings.
32.742368, 130.26004
