Outdoor onsen (rotenburo) in Kanagawa

Hakone · Multiple outdoor baths mentioned; rock-carved bath with river views; partially open-air design noted.

Yokohama · Visitors described an outdoor bath area including a carbonated-spring outdoor pool with a TV.

Hakone · Six outdoor baths set in forest; multiple reviews praise the natural forest setting and forest views.

Hakone · Multiple 2026-08 reviews confirm outdoor rotenburo baths exist with variety and good views.

Hakone · Reference to outdoor conditions suggests outdoor bathing areas exist.

Yokohama · One visitor (2026-08) noted the outdoor bath area feels open and enjoyable.

Yokohama · Visitors described an appealing outdoor bath with good views in 2026.

Yokosuka · Multiple reviews (2025-2026) describe an ocean-view outdoor bath, sometimes with two temperature options.

Kawasaki · Visitors praised the outdoor bath, describing both indoor and outdoor baths as spacious.

Chigasaki · Multiple visitors in 2026 described an outdoor bath area with a large carbonated pool, jar bath, and reclining bath with TV.

Yokohama · The facility has an outdoor bath area in addition to indoor baths (2026).

Hakone · The facility has outdoor baths with mountain views.

Yokohama · Multiple outdoor baths are available, one of which has a roof for shade or rain.

Kawasaki · Visitors describe two outdoor bath tubs that are relaxing, especially on cooler or quieter days.

Kawasaki · Outdoor bath present, surrounded by trees and rocks from Mt. Yatsugatake, one per gender; uneven floor and slippery surface noted as hazards.

Yokohama · Outdoor bath confirmed with TV, night sky view, and multiple bath types (2026-08, 2026-09).

Yokohama · Multiple outdoor baths use the black mineral water, arranged in tiered pots and larger tubs.

Atsugi · There was one outdoor bath featuring a cloudy 'Kusatsu-style' hot spring water.

Hiratsuka · Multiple 2026 reviewers described enjoying the outdoor bath area along with the sauna.

Yokohama · Reviews from 2026 describe an outdoor bath area with upper and lower tubs plus lounging seats.

Odawara · There is a rooftop outdoor bath in addition to indoor tubs.

Hadano · The facility has an outdoor bath alongside the indoor bath, each using a different spring source.

Yokohama · Visitors described an outdoor black-water bath with both hot and warm sections.

Kamakura · There is an outdoor-style bath, but reviewers note it is small and only partially open to the sky.

Atsugi · Multiple visitors describe a rooftop outdoor bathing area with several tubs (2026-05 to 2026-08).

Yokohama · The facility had an open-air outdoor bath area, unusual for the region.

Atsugi · The facility has an outdoor stone bath in addition to the indoor bath.

Sagamihara · Multiple reviewers described an outdoor bathing area with several pools including a source-heated bath, rock bath, and jar baths.

Hakone · Multiple outdoor baths present; visitors describe three outdoor baths with views of Hakone mountains and landscape.

Yokosuka · Multiple visitors described an open-air bath overlooking the harbor and ferries.

Chigasaki · Multiple reviewers describe a large outdoor bath area with jar baths and other pools.

Fujisawa · Reviewers described a rooftop open-air bath in addition to indoor baths.

Fujisawa · A cave-concept bath open to sea breeze with an ocean view directly in front was described.

Yokohama · Reviewers described a small outdoor bath as part of the communal baths.

Yokohama · Multiple outdoor bath tubs were reported, accessed via a stairway noted as slippery.

Hadano · The facility has an outdoor bath, recently renovated with new gravel and previously a cypress tub.

Sagamihara · Reviewers repeatedly describe a black hot-spring outdoor bath with a large TV.

Hadano · Multiple reviewers from 2026-06 to 2026-08 described an open-air outdoor bath area with several tubs.

Sagamihara · Reviewers repeatedly praised the outdoor rock bath as the highlight of the facility.

Yamato · Multiple visitors describe a rooftop outdoor bath with several types (2026).

Ebina · Multiple reviewers from 2026-05 to 2026-08 described using outdoor baths including foot-massage pools.

Minamiashigara · Multiple reviewers from 2026 describe a forest-surrounded outdoor bath with lukewarm water around 38°C.

Yokohama · There is an open-air bath, though one visitor noted it is roofed and lacks an open feeling while others enjoyed it (2026).

Yokohama · Visitors from 2026-06 to 2026-08 described multiple outdoor baths surrounded by trees and bamboo.

Zama · Multiple outdoor bath types including a waterfall bath, herbal bath, and natural spring black-water bath were reported.

Yokohama · The facility has outdoor baths, including a source outdoor bath and carbonated outdoor bath, though one reviewer noted a barbecue-exhaust smell in the men's outdoor bath.

Ebina · Visitors described an outdoor area with jar baths, rock baths, and a foot bath, sometimes nearly empty on weekdays.

Hakone · Multiple outdoor baths reported; one visitor counted 3 outdoor baths (males); all praise outdoor bath variety.

Hadano · An outdoor bath is present, sometimes offering mountain or Fuji views.

Sagamihara · The facility has a roofed outdoor bath enjoyed by visitors for its scenery.

Yugawara · Outdoor bath present at the facility; each bath type (large and small indoor) has a separate outdoor section, partially or fully enclosed.

Yokohama · The facility has an outdoor bath and outdoor rest/air-bathing area used after the sauna.

Sagamihara · The facility has an outdoor bath praised for its mountain view and sunset.

Odawara · Multiple reviewers described enjoying the open-air (rotenburo) bath with varied seating and water temperatures.

Fujisawa · Multiple reviewers from 2026-06 to 2026-08 confirm an outdoor bath area with several tub types.

Yokohama · Reviewers described a spacious outdoor bath area including a carbonated brown-water bath and a reclining bath.

Hakone · Outdoor bath with view of Lake Ashi and Mount Fuji confirmed by multiple visitors (2026-03 to 2026-09).

Hakone · Reviewers disagreed on the communal bath: one said there was no outdoor bath (2026-07), another described a small semi-outdoor jacuzzi (2026-04).

Yokosuka · There is an outdoor bath area, described as spacious but enclosed by walls with no view.

Yamakita · An outdoor bath exists but several reviewers in 2026 noted debris or poor drainage in it.

Yokohama · An outdoor bath surrounded by bamboo is mentioned repeatedly, sometimes lit up at night.

Yokohama · Visitors describe an outdoor bath, including a black-water version, as part of the facility.

Yokohama · An outdoor bath area exists, though one 2026 visitor felt it was on the small side.

Yugawara · Multiple reviews across 2025-12 to 2026-09 describe outdoor baths including a cave bath and two types of waterfall baths.

Kiyokawa · A small outdoor bath is present, described by several as hotter than the indoor bath and limited in capacity.

Yokohama · An outdoor bathing area with walking bath, herbal bath and other tubs existed.

Yokohama · Reviewers describe a half-open-air (han-roten) black-water bath in addition to indoor tubs.

Hakone · Communal baths include multiple outdoor varieties (tsubo, cave, waterfall-style, reclining); guest rooms have private outdoor baths.

Kawasaki · An outdoor black-water bath on the second floor was repeatedly praised in 2026 reviews.

Yokohama · Standard section has two small outdoor baths; Royal section has one larger outdoor bath with flowing water.

Hakone · Reviewers consistently describe an outdoor bath as the main facility for day-use visitors.

Hakone · Multiple visitors confirm outdoor/rotenburo baths exist; one mentions cave-carved bath.

Atsugi · The main communal bath includes an outdoor open-air section alongside the indoor bath.

Yugawara · Multiple reviews report outdoor baths available for day-use visitors from 2025 through 2026.

Hakone · Multiple reviews (2025–2026) describe outdoor rock baths and direct exposure to forest; cypress bath has partial roof.

Hakone · Outdoor bath available to day-use and lodging guests; guests noted it has no handrails (2025-09) and cleanliness concerns (2025-09).

Yokohama · An outdoor bath is available on both floors, described as lukewarm to cool depending on season.

Kawasaki · A semi-open-air (han-roten) bath was a regular feature noted across many years of reviews.

Yokohama · Reviewers across 2025-2026 describe a natural black-water outdoor bath.

Yamakita · Reviewers described a small outdoor bath in addition to the indoor bath.

Kamakura · A small outdoor rock bath exists, accessed via a built-in staircase above the main bathing area.

Yokohama · An outdoor bath with rotating medicinal (yakuyu) water was consistently reported from 2024 to the facility's closing in 2025.

Yokosuka · Multiple reviewers from 2025-04 to 2026-07 describe an outdoor bath with ocean views, though some also report parts of it out of service.

Yokohama · An outdoor bath is present alongside the indoor tubs, consistently mentioned from 2025 to 2026.

Yokohama · An outdoor bath area with jar-shaped tubs and carbonated water is present.

Kawasaki · Reviewers across 2025-2026 describe an outdoor bath with black (kuroyu) water, reached by a small staircase.

Yokohama · Both floors have an outdoor bath area, described as roofless with open-air seating.

Miura · The facility had an outdoor bath with ocean views, reported across 2023 and 2024 reviews.

Yokohama · Outdoor bath present; described as small (approx. 4.5 mats), with both plain and jet bath versions depending on day.

Yokosuka · Reviewers across years describe a small outdoor bath kept around 42°C even in winter.

Yokohama · The paid upper-floor 'Royal Zone' includes an open-air bath, mentioned by many reviewers from 2024 to 2026.

Yokohama · An outdoor bath was frequently praised, but multiple reviews note it existed only on the men's side, with women's side having an indoor rock bath instead.

Kawasaki · Reviewers across 2023-2026 consistently describe an outdoor natural hot-spring bath and adjoining cold outdoor bath.

Yokohama · Reviewers across 2024-2026 consistently describe an open-air outdoor bath section, sometimes with a roofless area and seating.

Yugawara · Main bath and private baths are semi-open or fully outdoor, located beside a river.

Kawasaki · Visitors consistently mention an outdoor or semi-outdoor bath area from 2024 through 2026.

Yokohama · There is a single small outdoor bath area with a shower massage and electric bath, accessible on alternating days depending on which side is men's or women's.

Kawasaki · Outdoor bath repeatedly mentioned; noted as small (3-person capacity), stone/rock style, scenic with view of night sky; explicitly stated as not a hot spring by at least one reviewer.

Aikawa · An open-air rotenburo exists, though as of March 2026 the separate outdoor-air bath section was not usable.

Hakone · Outdoor/semi-outdoor bath confirmed in multiple reviews; one reviewer notes the structure is not fully exposed to sky (walls connect to ceiling).

Yokosuka · An outdoor herbal bath, generally cooler than the indoor tubs, is mentioned in nearly every review from 2024 to 2026.

Yokohama · An outdoor black-water rotenburo with a waterfall bath (utaseyu) is available, alternating between the men's and women's sides by day.

Yokohama · Visitors across many years describe a small open-air bath open to the sky.

Fujisawa · Reviewers from 2025-2026 described a small outdoor bath alongside the main indoor tub.

Kawasaki · Outdoor bath area with multiple options including lounging tub and electric bath; outdoor washing stations also present.

Kawasaki · Many visitors from 2021 to 2026 describe a spacious outdoor bath, sometimes with a roof, praised as the facility's highlight.

Kawasaki · An outdoor bath (mainly on the women's side) exists but was reported as closed or opening irregularly in 2022-2025.

Kawasaki · Outdoor or partially open-air bath (silk bath) with fresh air exposure and garden view (2022-10 to 2026-08).

Yokosuka · The facility has an open-air herbal medicinal bath (yakuto), noted consistently from 2025 to 2026.

Hakone · Semi-open or roofed outdoor bath surrounded by bamboo forest with river views (2020–2024).

Yokohama · There is a small semi-open-air artificial carbonated bath, though several visitors note it is only partly outdoors and can be buggy in summer.

Kawasaki · Women's area has outdoor bath with rocks and benches; cypress bath in men's area is indoor or semi-outdoor.

Kawasaki · The facility has an outdoor bath area used for open-air relaxation after sauna or bathing.

Atsugi · Reviewers from 2025 and 2026 confirmed an outdoor bath in addition to the indoor bath.

Hakone · Two outdoor baths are present: one rock bath and one cypress bath, with forest views.

Kawasaki · Visitors from 2020 to 2023 repeatedly mention an outdoor bath (rotenburo) as a highlight of this sento.

Zama · Reviewers from 2019 to 2023 describe several outdoor bath pools, some spacious and some smaller.

Hakone · Outdoor bath available with views of Mt. Fuji on clear days.

Hakone · Outdoor bath and sauna present (2023-10).

Hakone · A semi-outdoor bath is available on the second floor alongside the indoor bath.

Hakone · An outdoor bath with sulfur scent and acidic character confirmed in May 2026.

Yugawara · Multiple outdoor baths confirmed in April 2026 review.