Kamata Onsen

On the way to this old-school bathhouse, you won't miss the big red sign that says 'Kamata Onsen' in Japanese. Soak in their rare black hot spring, which is said to heal back pain and give you healthy skin. In addition to that quirky speciality, you can experience all kinds of baths here, from high and low temperature ones to bubble and electrical baths, while the facility also houses a sauna. Head to the second floor and enjoy karaoke while grabbing some food and drinks.