On December 1, 2026, Kai Unzen (界 雲仙), a hot spring inn in Nagasaki's Unzen Onsen, will open two new spots where guests can experience the breath of Unzen Jigoku (雲仙地獄), the area's steaming volcanic hot spring fields. The inn is built around the concept of "an exotic inn where you can feel the power of Jigoku." One new spot is the "Jigoku Steam Observatory" (地獄の湯けむり展望台), a hilltop viewpoint from which guests can watch Unzen Jigoku change appearance between day and night. The other is the "Steam Lounge" (湯けむりラウンジ), which connects the real Jigoku with the relaxing spaces inside the inn. Together with a steam-themed setting and a special pudding, the two spots offer ways to enjoy the energy of Unzen Jigoku both inside and outside the inn.
Feature 1: The "Jigoku Steam Observatory" Overlooks Unzen Jigoku and Shows Steam in a Different Light by Day and Night
A hilltop spot with a view of Unzen Jigoku, the "Jigoku Steam Observatory," will be added to the grounds of Kai Unzen. From here, guests can observe "kanzuke" (燗つけ, see note 1 below), a mechanism unique to Unzen Onsen that uses high-temperature steam, and take part in "Onsen Culture Iroha" (温泉文化いろは, see note 2 below), an experience that explores Unzen's rich hot spring culture and the workings of the land.
The view changes with the time of day. During the day, the kanzuke mechanism can be seen clearly. At night, the outlines of the steam stand out against the darkness, conveying the lively, dynamic energy of the earth. The hilltop can be entered only by guests staying at Kai Unzen.
- Note 1: Kanzuke (燗つけ) is a hot-water supply mechanism that heats water using the high-temperature volcanic steam and geothermal heat of Unzen Jigoku.
- Note 2: Onsen Culture Iroha (温泉文化いろは) is a time to engage deeply with a region's distinctive hot spring culture, going beyond simply soaking in the water.
Onsen Culture Iroha Overview
| Period | Year-round |
| Time | 4:05 PM and 7:05 PM (about 20 minutes each) |
| Location | Jigoku Steam Observatory |
| Price | Free |
| Capacity | None |
| Reservations | Not required |
Feature 2: The "Steam Lounge" Connects Unzen Jigoku and the Inside of the Inn
The "Steam Lounge" is a new space linking Unzen Jigoku with the interior of the inn. Making use of its special setting, directly connected to Unzen Jigoku, the lounge is designed around the theme of steam and filled with billowing plumes. Guests can feel the pulse of Jigoku up close and touch steam they normally could not, as if they had stepped into Unzen Jigoku itself.
Feature 3: "Steam Pudding" Inspired by Steam of About 120°C, Enjoyed Through Presentation and Flavor
The Steam Lounge serves "Steam Pudding" (湯けむりプリン), an original sweet created by Kai Unzen. It takes inspiration from the steam of about 120°C that rises powerfully from Unzen Jigoku, and the pudding itself is steamed at about 120°C. It is served with a presentation in which steam rises right before the guest's eyes. The pudding is topped with a generous helping of a special cream meant to resemble soft steam, so guests can take in the atmosphere of the steam through both sight and taste while thinking of the dynamic energy of Unzen Jigoku.
Steam Lounge Overview
| Period | December 1, 2026 – May 31, 2027 |
| Time | 2:30 PM to 5:00 PM. The steam presentation is held for 5 minutes at 3:00 PM, 3:30 PM, 4:00 PM, 4:30 PM, and 5:00 PM |
| Price | Lounge use is free. Steam Pudding is ¥800 (tax included) |
| Location | Travel Library (トラベルライブラリー) |
| Capacity | None |
| Reservations | Not required |
Kai Unzen (Unzen Onsen, Nagasaki Prefecture)
Kai Unzen stands in a place where guests can feel Unzen Jigoku up close. The interior is furnished to express Nagasaki culture, a blend of Japanese (Wa), Chinese (Ka), and Dutch (Ran) elements. Through their stay, guests can experience the power of Jigoku by bathing in the hot spring and joining activities that make use of Jigoku. It is a hot spring inn where guests can enjoy the colorful, exotic culture and the energy of the earth coming from Jigoku.
- Address: 854-0621 Nagasaki Prefecture, Unzen City, Obama-cho Unzen 321 (〒854-0621 長崎県雲仙市小浜町雲仙321)
- Phone: 050-3134-8092 (Kai Reservation Center)
- Rooms: 51 (16 rooms with private open-air baths, 1 special suite)
- Rate: From ¥28,000 per night (per person, based on 2 guests sharing a room; tax included; dinner and breakfast included)
- Access: Approximately 1 hour by car from Isahaya Station; approximately 1 hour 30 minutes by car from Nagasaki Airport (shuttle service available)
- Website: https://hoshinoresorts.com/ja/hotels/kaiunzen/
