Guide
Tombo-no-yu is a natural hot spring facility located in the scenic Hoshino area of Karuizawa, Nagano Prefecture. The facility is characterized by its high-quality, free-flowing spring water (genzen kakenagashi) and is surrounded by a lush, tranquil forest. The indoor baths are designed with large windows to ensure guests feel a seamless connection with the surrounding nature. A major highlight is the ability to experience the changing seasons through the scenery and special seasonal waters.
Since its opening in 1915, Hoshino Onsen has been celebrated as a premier hot spring destination in Karuizawa, a famous summer resort. Historically, this area has been a retreat for many intellectuals and cultural figures. Today, the facility continues this tradition, serving as a place where visitors can rejuvenate their spirits while preserving the pristine natural environment that has made the area famous for over a century.
The facility features spacious open-air baths and indoor baths designed to create a sense of unity with nature. The cold water bath (mizufuro) uses fresh spring water from the nearby Wild Bird Forest, ensuring a stable and refreshing temperature throughout the year. Additionally, near the entrance, you can find the 'Shinra Hyakusen' exhibition, which features rotating calligraphy and paintings that change with the seasons, offering a different cultural atmosphere every time you visit.
Each season offers a unique visual experience. In spring, enjoy the budding greenery and cherry blossoms; in summer, the deep, vibrant greens of the forest; in autumn, the stunning colors of the changing leaves; and in winter, the serene, snow-covered landscapes. Specifically, during autumn, you can soak in the hot spring while admiring the vibrant foliage. The facility also hosts seasonal events, such as 'Apple Bath' in autumn or 'Yuzu Bath' during the winter solstice, providing a unique sensory experience.
Beyond the hot spring soak, guests can enjoy a premium sauna experience. The facility features a 'Bona Sauna' with a temperature of approximately 85–90°C (185–194°F), which automatically pours water onto the heat source every 20 minutes to maintain optimal humidity. The combination of the sauna and the cold water bath (using fresh spring water) provides a perfect cycle for relaxation. There is also a dedicated outdoor air-cooling area (gaikiyoku) where you can breathe in the crisp, clean forest air.
Located within the Hoshino area, the facility is surrounded by various spots where you can fully enjoy the natural beauty of Karuizawa. It is an ideal stop during your sightseeing tours around the area, allowing you to easily transition from walking through nature to relaxing in the hot springs.
Please observe the following rules for a pleasant experience. First, always wash your body thoroughly before entering the bath. Long hair should be tied up and kept out of the water. Do not bring towels into the bathwater. The use of smartphones or electronic devices in the changing rooms and bathing areas is strictly prohibited. Regarding tattoos, guests may enter if the tattoo is covered by a designated waterproof cover sticker (minimum 10x8cm), which can be purchased at the reception. For guests with infants, baby baths are provided. Please note that the use of hair dye, colorants, or hair manicures is strictly prohibited in the changing rooms, baths, and restrooms.