About
Representative volcanic caldera landscape similar to Mt. Mihara views from the onsen
Oshima Onsen Hotel (大島温泉ホテル / Miharayama Onsen Resort) is a classic Japanese onsen hotel located at the 8th station of Mt. Mihara on Izu Oshima Island, offering day-visit bathing with spectacular volcanic mountain views. 🔗 The hotel's outdoor baths (rotenburo) provide unobstructed panoramic views of Mt. Mihara (758m), the island's active volcano, across a vast sea of primeval forest. 🔗
The onsen draws from a volcanic hot spring source at 300 meters underground, producing water at 69°C or higher that flows continuously (gensen kakenagashi - source-fed flowing style). 🔗 This geothermal activity is directly connected to Mt. Mihara's volcanic energy, making it a quintessential volcanic onsen experience in the Izu Islands.
Cultural & Historical Significance
The cultural significance of volcanic onsen bathing in Japan traces back over 2,000 years, rooted in Shinto purification rituals (misogi) and Buddhist healing traditions. 🔗 Hot springs are considered sacred places that cleanse both body and soul, with volcanic mineral waters prized for their therapeutic properties. 🔗 The practice of touji (湯治) - therapeutic bathing for health restoration - has been central to Japanese wellness culture for centuries. 🔗
Oshima Onsen Hotel embodies this tradition while offering direct connection to Mt. Mihara, the sacred volcano revered by islanders as "Gojinka-sama" (Lord Sacred Fire). The outdoor baths allow visitors to soak in geothermally heated waters while contemplating the active volcanic crater that provides this natural heat—a profound experience of living "in the middle of a volcano" as islanders describe their relationship with Mt. Mihara. 🔗
Access Information
From Motomachi Port or Okata Port:
- Distance: Approximately 20 minutes by car 🔗
- Free shuttle bus available from either port (reservation recommended) 🔗
- Shuttle aligns with afternoon jet foil arrivals 🔗
By Local Bus:
- From Motomachi Port: Take Oshima Bus bound for Miharayama Summit (三原山頂口行き), get off at "Miharayama Onsen" stop (三原山温泉下車) - approximately 18 minutes 🔗
By Car:
- Located almost in the center of Izu Oshima at the foot of Mt. Mihara
- Free parking available (30-50 spaces, no height restrictions) 🔗
Operating Hours for Day Visitors:
- Morning session: 6:00 AM - 9:00 AM
- Afternoon/evening session: 1:00 PM - 9:00 PM (last entry)
- Closed annually: October 6-10, 2025 for facility maintenance 🔗
Admission Fees:
- Standard day-visit bathing: Adults ¥800, Children ¥400 🔗
- Breakfast rest plan (reservation required): Adults ¥2,300, Children ¥1,900 (tax included) - Available 6:00-9:00 AM on days when large ferries arrive from Tokyo 🔗
The Bathing Experience
Outdoor Baths (Rotenburo): The highlight of Oshima Onsen Hotel is the gender-separated outdoor baths with panoramic Mt. Mihara views. Both male and female outdoor baths offer unobstructed vistas across primeval forest to the volcano's caldera and lava flows beyond. 🔗 On clear days, bathers can see Mt. Mihara's summit (758m), and occasionally Mt. Fuji and the Izu Peninsula in the distance. 🔗
The outdoor pools accommodate approximately 30 people and maintain natural volcanic water temperatures through continuous source-fed flow. 🔗 The volcanic mineral content includes sulfur and other geothermal elements beneficial for skin health and muscle relaxation.
Indoor Baths: Each gender has one large indoor bath in addition to the outdoor rotenburo. The indoor facilities provide shampoo, conditioner, and body soap. 🔗 Both baths operate from 1:00 PM-12:00 AM midnight and 5:00-9:00 AM. 🔗
Additional Features:
- Terrace with Mt. Mihara views (open 3:00-9:30 PM) for post-bath relaxation and stargazing 🔗
- Changing facilities with lockers
- Vending machines
- Small shop
Practical Visiting Tips
November Seasonal Considerations:
- Weather & Comfort: Daytime temperatures ~17°C / Evening: 11-13°C. Outdoor bathing highly comfortable in these temperatures. 🔗
- Hot volcanic water: Maintained at bathing temperature from 69°C source, contrasts beautifully with cool autumn air
- Rainfall: Expect some rain—check weather forecasts for clear Mt. Mihara viewing opportunities
- Visibility: Autumn in Japan is considered one of the best seasons for outdoor onsen experiences 🔗
Best Visiting Times:
- Sunset bathing highly recommended for Mt. Mihara summit views 🔗
- Clear weather essential for volcano views—check forecast before visiting
- November afternoon sessions (1:00-5:00 PM) offer good lighting for photography and comfortable outdoor bathing temperatures
- Combine with Mt. Mihara trekking—many visitors use the onsen after hiking 🔗
Photography Conditions:
- Afternoon light (1:00-4:00 PM) ideal for Mt. Mihara photography
- Sunset viewing (around 4:30-5:00 PM in November) from outdoor baths is spectacular 🔗
- Clear mornings offer best volcano visibility
- Photography NOT permitted inside bathing areas (standard onsen rule)
- Terrace area allows photos of Mt. Mihara views
Onsen Etiquette:
Pre-Bathing Requirements:
- Wash thoroughly at washing stations before entering any bath 🔗
- Complete nudity required—no swimsuits or towels in baths 🔗
- Small hand towel may be carried but must not touch bath water
- Gender-separated facilities (no mixed bathing)
Cultural Considerations:
- Conversation should be hushed and respectful 🔗
- No excessive splashing or swimming
- Tie long hair up
- Remove all jewelry and accessories before bathing
- Tattoos may need to be covered or disclosed (check with staff)
What to Bring:
- Towel rental available (paid service) 🔗
- Alternatively, bring your own small towel (for washing) and large towel (for drying)
- Basic toiletries provided (shampoo, conditioner, body soap)
- Bring exact change for admission (¥800 adults)
- Warm clothing for post-bath transition (11-13°C evenings)
- Waterproof jacket recommended due to November rainfall potential
Optimal Itinerary Sequence:
- Morning arrival by ferry or flight
- Mt. Mihara hiking/sightseeing (morning-early afternoon)
- Oshima Onsen Hotel bathing (afternoon 1:00-5:00 PM)
- Evening return to Tokyo
Crowd Avoidance:
- Weekdays generally quieter than weekends
- Early afternoon (1:00-2:00 PM) tends to be less crowded
- Avoid peak arrival times after major ferry dockings
- November off-season likely has lighter crowds than summer
Comparison with Hama-no-Yu: Oshima Onsen Hotel offers traditional gender-separated naked bathing with mountain/volcano views (¥800), while Hama-no-Yu offers cheaper mixed-gender swimsuit bathing with ocean views (¥300). 🔗 Choose based on preference for traditional onsen culture (Oshima Onsen Hotel) versus accessible seaside experience (Hama-no-Yu).
Important Notes:
Facility Maintenance Closure: October 6-10, 2025 - hotel completely closed during this period. 🔗
Weather Dependency: Mt. Mihara views are the primary attraction—confirm clear weather forecasts before traveling to Oshima for the onsen experience. Cloudy or rainy conditions significantly diminish the outdoor bath experience.
Transportation Planning: Coordinate arrival times with shuttle bus service or arrange car rental/taxi in advance. Public bus service exists but may have limited frequency.
Reservation Not Required: Day-visit bathing is walk-in basis, but shuttle bus service may require advance notice.
Location: View on Google Maps
Source: attractions/ooshima/oshima-onsen-hotel.md