Raicho-so

Access is quite difficult, requiring multiple public transportation transfers followed by a 30-40 minute walk from the Murodo Terminal. The path includes elevation changes and has elements of a trekking course.

The operating period is limited to mid-April through late November, with complete closure during the winter season.

The water quality is very distinctive, with strongly acidic hot springs being relatively rare in Japan. Although water is added, it maintains the quality of genuine hot spring water with flowing water directly from the source.

The location is at a very high altitude of 2,400 meters, surrounded by harsh natural conditions including hydrogen sulfide gas drifting from Jigokudani Valley.

The surrounding area is primarily frequented by hikers and trekking enthusiasts, with most general tourists turning back at Mikurigaike Onsen, limiting the number of people who venture further to reach Raichoso.

However, the well-equipped facilities, including panoramic baths, restaurants, and Wi-Fi services, give it aspects of a "mountain resort" rather than a completely hidden hot spring. Additionally, day-trip bathing is available, making it accessible to anyone willing to make the journey, which means it is not entirely a hidden hot spring.