Tokyo Tennen Onsen - Kodai Hot Spring
Good to know before you go
- Getting there
- Shin-Koiwa Station · 20 min walk (JR Sōbu Main Line, JR Chūō-Sōbu Line)
- Hours
- 10:00–23:00 (last admission 21:30)
- Admission
- ¥2,680 (junior high school and older), ¥1,320 (ages 0 to elementary school; includes towels and loungewear)
- Time needed
- 2–4 hours
- Best time to go
- Weekday daytime, when visitor traffic is lowest and facility-wide discount rates frequently apply.
Hours can change on holidays — check the official site before travelling.
About
Located in Tokyo's quiet Katsushika ward, this massive three-story public bathhouse offers a authentic, retro-style escape from the city center. It is highly worth visiting for its mineral-rich, amber-colored natural hot spring water pumped from deep underground, which feeds both indoor and open-air cypress baths. Beyond the baths, you can expect a full day of relaxation with spacious rest lounges, massage services, and a traditional restaurant with tatami seating.
What Japanese guides note
While the bathhouse is situated roughly 20 minutes on foot from Shin-Koiwa Station, visitors generally rely on the complimentary shuttle buses that run from the station rotaries of Shin-Koiwa, Aoto, Kameari, or Kanamachi. Standard admission automatically includes bath linens and loungewear, which guests collect at the second-floor service desk before entering the changing quarters. All forms of tattoos and body art remain strictly prohibited across the premises.
Details from local sources
- The facility pumps fossil seawater from a depth of 1,720 meters, yielding a weakly alkaline (pH 7.8) iodine-containing sodium-chloride strong salt spring. [source]
- The open-air baths are arranged in three cascading tiers set to different water temperatures, descending from 40–42°C at the top to 38–40°C at the bottom. [source]
- Both men's and women's bath areas contain a walking bath lined with river cobblestones designed to apply pressure to foot reflex points. [source]
- Free shuttle buses connect the onsen directly with four railway stops: JR Shin-Koiwa, Keisei Aoto, JR Kameari, and JR Kanamachi. [source]
- The fourth floor contains a 350-tatami dining hall equipped with a stage hosting live song and theatrical shows. [source]
- Free beverage dispensers outside the locker rooms provide complimentary hot and cold water, deep-steamed green tea, and roasted hojicha. [source]
- The facility enforces a complete ban on tattoos, temporary tattoo stickers, and body paint, with no admission refunds given upon ejection. [source]
Insider Tip
Take the free shuttle bus from Shin-Koiwa, Kanamachi, or Kameari stations to save on taxi fare and avoid a long walk.
Frequently asked
How do visitors reach the bathhouse using public transit?
Although Shin-Koiwa Station is a 20-minute walk away, walking is uncommon. The facility operates dedicated complimentary shuttle buses between the complex and four surrounding rail hubs: JR Shin-Koiwa (South Exit), Keisei Aoto, JR Kameari, and JR Kanamachi. Timetables and pickup zones are posted on the official website.
Are tattoos or body art permitted inside the baths?
No. Kodai no Yu enforces a strict ban on all body art. Guests bearing visible tattoos, temporary transfer stickers, or painted designs are prohibited from entering. Staff will immediately eject any guest found in violation inside the baths without issuing an admission refund.
What amenities are included with the admission fee?
Admission covers access to all general indoor baths, open-air pools, and saunas, alongside a rental set comprising a washcloth, bath towel, and馆内着 loungewear. Shaving kits, toothbrushes, toiletries, and self-serve cold or hot green tea dispensers outside the changing rooms are also free.
What type of spring water does the facility provide?
Water is extracted from 1,720 meters underground and consists of prehistoric fossil seawater classified as an iodine-containing sodium-chloride strong salt spring. Its concentrated salinity warms the body deeply and retains heat, targeting muscle stiffness, chronic nerve pain, and poor peripheral blood circulation.
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