Mizunoto

A diverse selection of 13 bathing spots spanning the two hot springs of Kowakudani and Miyanoshita, plus two saunas standing quietly in the stillness

Kanagawa Hakone Town, Ashigarashimo District

"Hakone Kowakudani Onsen Mizunoto" is a hot spring ryokan in Hakone Town, Ashigarashimo District, Kanagawa Prefecture. Nestled in the lush tranquility of Kowakudani, this inn offers soothing murmuring water and a clean, refreshing atmosphere. Inside, it draws from two of Hakone's 17 hot springs, "Kowakudani Onsen (Mizuhanosho)" and "Miyanoshita Onsen (Mizukinosho)," allowing guests to enjoy luxurious hot spring hopping across a total of 13 baths with distinct character, including 4 large public baths and 3 free private open-air baths. The large public baths in Mizukinosho feature two types of saunas: a spacious sauna in the indoor bath area and a compact sauna in the open-air area. Each is paired with a uniquely designed cold plunge bath, creating a lavish bathing experience.

Hot Spring & Bath Information

Mizukinosho Large Public Bath, Miyanoshita Onsen

TypeNatural Hot Spring

The two large public baths, Tsuki no Yu and Hoshi no Yu, located in Mizukinosho, the main building. They draw from the famous Miyanoshita Onsen, a hot spring renowned on par with Owakudani, and can be enjoyed in an indoor bath overlooking the changing seasons through large windows, an open-air cypress bath with a view of vibrant new greenery, and an atmospheric stone bath. Thanks to the chloride spring, they offer excellent moisturizing and warming effects, with a pleasantly smooth feel that makes this a beautiful skin hot spring.

Mizuhanosho Large Public Bath, Kowakudani Onsen

TypeNatural Hot Spring

The two large public baths, Hana no Yu and Sasa no Yu, located in Mizuhanosho, the new building. These baths draw from Kowakudani Onsen. At Sasa no Yu, guests can enjoy ishikiriburo baths, including a hot bath and a lukewarm bath. At Hana no Yu, they can savor the luxury of a free-flowing cypress indoor bath, as well as a reclining bath and an open-air stone bath where they can lie back and enjoy a forest bath. Combining the cleansing effects of a bicarbonate spring with the heat-retaining benefits of a chloride spring, this is an exceptional hot spring that helps keep you warm long after bathing.

Private Open-Air Bath Mori no Yu

TypeNatural Hot Spring

Flow-through

Three tasteful private open-air baths set within the garden: Momiji, Koyo, and Hana Hinoki. If available, they can be used freely without reservation, as many times as you like, for no charge. Fresh spring water is used as free-flowing water straight from the source, so you can indulge in the ultimate private bathing experience without worrying about being seen, while fully enjoying the sights and sounds of Hakone's abundant nature, including the murmuring streams and water sounds, with all five senses.

Sauna

Tsuki no Yu Dry Sauna

85°C

Sauna TypeDry Sauna

Stove TypeConvection Stove (Sauna Stone)

Capacity5people

Men'sWomen's

A clean, high-temperature dry sauna made of wood, located inside the indoor bath area of Tsuki no Yu in Mizukinosho (main building). A large sauna window is installed on the front wall, allowing guests to relax and sweat while gazing at the borrowed scenery of the garden beyond the open-air bath. The heat is gentle and never feels stifling, making it possible to spend a meditative time in quietness, easing away the fatigue of everyday life.

Hoshi no Yu Dry Sauna

85°C

Sauna TypeDry Sauna

Stove TypeConvection Stove (Sauna Stone)

Capacity2people

Men'sWomen's

A compact dry sauna room independently installed in the open-air area of Hoshi no Yu in Mizukinosho (main building). The sauna is entered after stepping out into the fresh air, and the borrowed scenery of the garden spreads beautifully beyond the open-air bath. In this small, private-feeling space for about 2 people, you can warm your body thoroughly in intensely hot conditions.

Cold Bath

Tsuki no Yu Indoor Cold Plunge Bath

18°C

Water QualityTap Water

Capacity2people

Men'sWomen's

A cold plunge bath located right next to the indoor sauna at Tsuki no Yu. Its highly unique layout seems to extend slightly out from the bathing room, with full glass walls throughout. You can enjoy a refreshing cooldown while being wrapped in pleasantly soft water and taking in the beautiful view of bamboo right in front of you, all with the sensation of being in another world.

Hoshi no Yu Open-Air Cold Plunge Bath

18°C

Water QualityTap Water

Capacity1people

Men'sWomen's

A one-person open-air cold plunge bath placed directly in front of the open-air sauna at Hoshi no Yu. It offers a luxurious setting where you can immerse yourself in cold water while feeling Hakone's crisp outdoor air and breeze directly on your skin. The excellent flow from sauna to bath also makes for smooth, direct access in just a few steps, bringing about a refreshed totonou feeling while looking up at the greenery.

Business Hours

Monday
14:00〜01:00
02:00〜11:00
Tuesday
14:00〜01:00
02:00〜11:00
Wednesday
14:00〜01:00
02:00〜11:00
Thursday
14:00〜01:00
02:00〜11:00
Friday
14:00〜01:00
02:00〜11:00
Saturday
14:00〜01:00
02:00〜11:00
Sunday
14:00〜01:00
02:00〜11:00
Holiday
14:00〜01:00
02:00〜11:00

Closed Days: None

Address

492-23 Kowakudani, Hakone Town, Ashigarashimo District, Kanagawa 250-0406

Hotel & Ryokan

Gender Access

Gender Separated

Tattoos in the Communal Bath
Unknown (Please Check)

The above applies to the communal (shared) baths. At facilities with private baths or private saunas, guests with tattoos may still be able to bathe. Please check with the facility for details.

Premium Magazine

Japan's Must-Visit Finest Onsen & Sauna Facilities

Curated by an expert who visits onsen and sauna facilities every day and has explored 300+ locations — only facilities confirmed to be truly exceptional are featured.

Learn more