Kagoshima · Sakurajima
Sakurajima Magma Onsen (Rainbow Sakurajima)
桜島マグマ温泉（国民宿舎レインボー桜島）
A day bath inside a public inn 15 minutes by ferry from Kagoshima port and 8 minutes' walk from Sakurajima port. Water rises at 51°C from a magma layer 1,000 m below, clouded rust-brown with iron, and flows freely through a bath hall looking across Kinkō Bay to the city. ¥460, 11:00–21:00 — a bargain after touring the volcano or the lava seaside trail. The free 100-metre Lava Nagisa Park footbath is within walking distance. Operations may be affected by volcanic alert levels.
- Price (adult)
- ¥460
- Hours
- 11:00–21:00 (reception until 20:00; from 13:00 on Wed for cleaning)
- Closed
- Open daily
- Access
- 15 min by Sakurajima Ferry from Kagoshima port, then 8 min on foot; or Sakurajima Island View bus to Rainbow Sakurajima
- Water type
- Iron spring
- Tattoos
- Ask ahead
- Admission
- Adults ¥460, children ¥150 (older sources quote ¥390) — very cheap, as a Kagoshima city-run kokumin-shukusha. Shampoo and body soap provided; bath-towel rental ¥300, hand towel ¥200. Family bath available (ask on site for rates). Free for hotel guests. Restaurant (lunch) and shop; free panoramic lobby
- Baths
- A panoramic bathhouse on the ground floor of a seaside public lodge, 8 minutes' walk from the Sakurajima ferry terminal. The wall facing Kinko Bay is all glass, with Kagoshima city across the water and ferries passing; the sunsets on a clear day are superb. One large indoor tub per gender (no outdoor bath), no sauna, plus a family bath. Brown, cloudy water from 1,000 m down overflows freely and stains the tub rim red with iron. Next door are the Sakurajima Visitor Center and the free 100 m foot bath at Lava Shore Park, among Japan's longest
- Spring water
- Sodium chloride spring (isotonic, neutral, high-temperature), 51.4°C at source, drawn from near the magma layer 1,000 m down — hence 'Magma Onsen'. Rich in iron and salt, brown and cloudy with a salty taste, reddening on contact with air. Free-flowing source (diluted to adjust temperature). A heat-retaining 'warming bath'. Indicated for neuralgia, muscle and joint pain, chronic digestive disorders, frozen shoulder, cuts and poor circulation. One of the few day-bathing facilities on the active volcano island of Sakurajima
- Access & parking
- 15 min on the Sakurajima ferry from Kagoshima port (24-hour service, adults ¥250), then 8 min on foot from Sakurajima port (left along the coast road). The Sakurajima Island View bus stops right outside at 'Rainbow Sakurajima'. Cars can cross on the ferry; free parking for 60. From Kagoshima-Chuo Station it is 15 min by city bus or tram to Suizokukan-guchi (ferry terminal)
- Phone
- 099-293-2323
- Official site
- rainbow-sakurajima.com ↗
- Open in Google Maps
- Google Maps ↗
Essentials
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Why go
- Rust-brown water heated by an active volcano
- Views over Kinkō Bay to the city
- ¥460, 8 min walk from Sakurajima port
¥460 in the lap of an active volcano, gazing across the bay at Kagoshima
Sakurajima Magma Onsen is a day-bath inside 'Rainbow Sakurajima', a city-run kokumin-shukusha lodge eight minutes' walk from the ferry terminal on Sakurajima, the still-smoking volcanic island in Kagoshima. The source rises at 51.4°C from near the magma layer 1,000 m underground, so rich in iron and salt that it is brown, cloudy and salty, overflowing freely and staining the tub rim red. Location is the great draw: the bay-side wall of the main bath is all glass, framing Kagoshima city across the water, the ferries that run round the clock and, on clear evenings, the sun setting into the sea. Because the city runs it, admission is an astonishing ¥460 with shampoo provided, and Kagoshima visitors love to stop here after touring the island — the lava shore trail, Yunohira lookout and the buried torii at Kurokami — before the ferry back. There is no outdoor bath or sauna, but pair it with the free 100-metre foot bath at Lava Shore Park next door for the complete 'volcano onsen' experience.
Red cloudy water and ferries beyond the glass
Pay at the lodge's front desk (free for guests) and follow the corridor to the gender-separated baths. The changing room is plain with free lockers, and the wash stations have shampoo and body soap. The bathroom itself is simple — one big tub and wash stations — but the whole bay-side wall is glass, so from water level you see the sea, Kagoshima city opposite and the ferries crossing every 15 minutes. The water is a brown cloudy soup with 20–30 cm of visibility, distinctly salty with an iron tang, the 51°C source diluted to around 42°C and overflowing freely. As a chloride spring it keeps you sweating long after, so several short dips beat one long soak. On Wednesdays cleaning delays opening to 13:00; late afternoon to just before sunset is the most beautiful time. Outside the bath a panoramic lobby overlooks the sea, and the restaurant (lunch around 11:30–14:00) serves local produce such as Sakurajima mini-mandarins and kurobuta pork. On days when ash falls, the windows may haze over depending on the wind — very Sakurajima. The facilities are not luxurious, so set expectations for 'the view, the water and the price'.
A half-day on Sakurajima with the ferry
Hours are 11:00–21:00 (reception until 20:00), open daily, except Wednesdays when cleaning delays opening to 13:00. Adults ¥460, children ¥150 (raised from ¥390); towels for rent or sale. The Sakurajima ferry sails round the clock from the Suizokukan-guchi terminal at Kagoshima port (every 15 minutes by day, 15-minute crossing, adults ¥250), and from Sakurajima port it is an 8-minute walk left along the shore. A good half day: Kagoshima port, ferry, the free Sakurajima Visitor Center with its volcano exhibits, the lava shore trail and 100 m foot bath, the Island View bus (one-hour loop, day pass ¥500) to the Yunohira lookout (373 m, the closest viewpoint to the crater) and the 'Portrait of a Shout' monument at Akamizu, back for a soak in the Magma Onsen, then the ferry home at sunset. With a car, add a 90-minute drive to the east side for the Kurokami buried torii (sunk 3 m by the 1914 eruption) and the Arimura lava lookout. An umbrella or hat helps when ash falls; with several hundred eruptions a year, small plumes are everyday. From a Kagoshima city hotel it is an easy outing before dinner, and if you stay a night on the island the bath is free for guests and you have the night view of Kagoshima across the water to yourself.
Before you go
- No official tattoo policy is published — ask at reception.
- Ryokan day-use hours are limited and may be suspended in peak season — phone the same morning.
- Payment is usually by ticket machine in cash — bring coins.
- Last entry is 30–60 minutes before closing.
Features
Mood & scenery
Rules & private
Price
Amenities
✔ Verified operating: 2026-09 Operating status and rates cross-checked against the official site and onsen guides (full source notes in Japanese on the JA page)
Prices and hours change. Check official sources before visiting.
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