Chiba · Kujūkuri / Shirako Onsen
Spa & Resort Kujūkuri Taiyō no Sato
スパ＆リゾート九十九里 太陽の里
One of the Bōsō peninsula's largest spa resorts, in Shirako on Kujūkuri Beach. Soak in iodine-rich, tea-coloured Chōsei spring water in the open-air bath, with seven rock-bath rooms, saunas, nap lounges, banquet halls and lodging on site. Open straight through from 10:00 to 08:00 the next morning; stays past 01:00 incur a late surcharge. Free shuttle from JR Mobara Station (reservation required). ¥1,600 weekdays, ¥1,900 weekends. Tattoos—including stickers and paint—are strictly refused.
- Price (adult)
- ¥1,600
- Hours
- 10:00–next day 08:00
- Closed
- Open daily (occasional maintenance closures)
- Access
- About 20 min by free shuttle from JR Mobara Station (Sotobō Line; reservation required); 25 min by car from Mobara-Chōnan IC
- Water type
- Simple spring
- Tattoos
- Not allowed
- Phone
- 0475-32-7777
- Official site
- www.taiyounosato.co.jp ↗
- Open in Google Maps
- Google Maps ↗
Essentials
Stay in this onsen town
Compare and book stays in Kujūkuri / Shirako Onsen. Day bathing itself needs no booking.
Opens partner booking site (affiliate)
Why go
- Open 10:00 to 08:00 next day
- Iodine-rich brown spring water
- Free shuttle from Mobara Sta.
Before you go
- Tattoos are explicitly not allowed, even if covered.
- Ryokan day-use hours are limited and may be suspended in peak season — phone the same morning.
- Last entry is 30–60 minutes before closing.
Features
Sauna & wellness
Who with
Price
Amenities
✔ Verified operating: 2026-09 公式サイト料金ページ（平日1,600円/土日祝1,900円・タトゥー不可）
Prices and hours change. Check official sources before visiting.
More in this area
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Kameyama Onsen Hotel
About 70 minutes from central Tokyo via the Aqua-Line, a hot-spring inn founded in 1950 on the shore of Lake Kameyama in the Boso hills. Its chocolate-brown 'kuroyu' bicarbonate water — billed as Boso's finest beauty bath — flows freely into a large bath with lake and forest views. Day use 11:30–18:00, ¥1,000 on weekdays; no day bathing Thursdays and Fridays. In autumn pair it with a foliage cruise on the lake.
Yoro Valley Onsen Sagawa
A 12-room inn in Yoro Valley, the Boso Peninsula's autumn-colour spot and the last place in the Kanto region to turn, peaking late November to early December. Boso's signature coffee-coloured alkaline 'black water' fills the indoor and open-air baths; day use is a flat ¥700 for ages 3 and up, 11:00–15:00. Eat lunch in the dining room and the bath is free — spring bamboo-shoot dishes are the speciality. Five minutes by bus from Yoro-Keikoku Station on the Kominato Railway to Yorokan-mae. Lunchtime opening can be suspended at short notice, so phone ahead.