Complete Guide to Unzen Hell: 30 Volcanic Vents & Christian Martyrdom History

Unzen Hell, spreading across Unzen City in Nagasaki Prefecture, is one of Kyushu's premier geothermal areas with over 30 scattered "hells" (volcanic vents). The sulfurous aroma fills the air while steam and heat erupting from deep underground cover the entire area - truly resembling "hell" itself.

However, Unzen Hell is not merely a tourist destination. During the Edo period, it became the tragic stage for Christian martyrdom and remains an important historical site in Japan's religious history.

This article provides a complete guide to all 30 hells of Unzen and the history and culture behind them.

What is Unzen Hell? Kyushu's Largest Geothermal Area

Overview of Unzen Hell

Unzen Hell is an area covered with white soil (hot spring sediment) spreading between Furuyudo and Shinyudo of Unzen Onsen. Composed of over 30 hells, high-temperature hot springs and steam violently erupt from everywhere.

Basic Data:

• Location: 320 Unzen, Obama-cho, Unzen City, Nagasaki Prefecture
• Number of Hells: Over 30
• Maximum Temperature: 120°C
• Spring Quality: Sulfuric acid sulfur spring
• Open Hours: 24 hours
• Admission: Free

Formation and Geological Value of the Hells

The energy source of Unzen Hell is believed to be the magma chamber beneath Tachibana Bay's seabed. High-temperature, high-pressure gas generated from this magma chamber rises through rock fissures, undergoing chemical changes to become high-temperature hot water. The violent steam emerges from gas produced by this hot water's boiling.

Through this geothermal activity, Unzen's hot springs are generated by mixing underground gas and groundwater from surrounding mountains.

Thorough Explanation of 30 Hells | Characteristics and Highlights of Major Hells

【Most Intense】Daikyokan Jigoku (Great Screaming Hell)

Located on the eastern side of Unzen Hell, this is the place with the most violent steam emission. Named after "Daikyokan Jigoku," one of Buddhism's hells.

Features:

• Steam phenomena observable up close
• Observation deck with stone monument
• Popular photo spot
• Most intense steam sounds

【Legendary Hell】Oito Jigoku

A hell that reportedly erupted in early Meiji period, with a sad female legend remaining.

Legend of Oito: There was a woman named Oito who lived prosperously in Shimabara castle town but killed her husband after an affair. When Oito was executed, this hell erupted, so it was named with the warning "disturb the family and you'll fall to hell."

Current State:

• Very active steam activity
• Adjacent to Unzen Hell Tea House
• Enjoy foot steaming experience and hot spring eggs

【Other Major Hells】

Seishichi Jigoku

• Hell named after a male name
• Medium-scale steam activity

Hachiman Jigoku

• Named after the number "eighty thousand"
• Multiple steam vents scattered

Jaken Jigoku

• Derived from Buddhist defilement "jaken" (wrong view)
• Relatively quiet steam

Other 20+ Small Hells Unzen Hell has many small unnamed hells, each showing unique expressions.

Christian Martyrdom History | The Tragic Past of Unzen Hell

Unzen Hell Christian Martyrdom Incident

From 1627 to 1632 over five years, torture demanding conversion was conducted at Unzen Hell as part of the Edo shogunate's Christian suppression. This incident became known overseas and moved many people's hearts.

Reality of Martyrdom:

• Thrown into sulfur-boiling hot pools
• Hot water poured over entire body
• Dozens of martyrs who still wouldn't abandon their faith

Path to Shimabara Rebellion

The harsh Christian suppression by Shimabara domain lord Matsukura Shigemasa and his son Katsuie eventually led to the Shimabara Rebellion (1637-1638). The torture at Unzen Hell symbolized the religious conflict behind this large-scale uprising.

Christian Martyrdom Monument

Currently, a Christian martyrdom monument stands on a hill overlooking the hells.

Monument Text (excerpt): "Do not fear those who kill the body but cannot harm the soul." Following this sacred teaching, valuing loyalty to God and dignity of the soul, the honor of holy martyrs who overcame torture and death through faith remains here forever.

Every third Sunday in May, a Christian martyrdom festival is held here to console the martyrs' spirits.

2016 Renewal! Interactive Hell Experience

From "Viewing Hell" to "Experiencing Hell"

Through autumn 2016 renewal, Unzen Hell transformed from traditional "viewing hell" to "experiencing hell." New spots for five-sense enjoyment have been established.

New Experience Spots

1. Unzen Hell Foot Steaming (Ashimushi)

• Experience geothermal heat and steam directly by placing feet
• Natural foot bath effects
• Also usable as rest area

2. Unzen Hell Workshop

• Sells hot spring eggs steamed with hell steam
• Enjoy fresh hot eggs
• Operating hours: 10:00-17:00 (year-round)
• Price: 2 eggs ¥200, 5 eggs ¥400

3. Unzen Hell Observation Deck (with Rest Area)

• Enjoy hot spring eggs while viewing surrounding hells
• Perfect photo spot

4. Mud Volcano

• Cone-shaped mountain formed by underground steam
• Grayish-white sticky soil quality
• Natural phenomenon changing shape daily

Hot Spring Egg Longevity Legend

Unzen Hell's hot spring eggs have an ancient legend:

• Eat 1 egg, live 1 year longer
• Eat 2 eggs, live 2 years longer
• Eat 3 eggs, live long until death

During busy autumn season, over 2,000 eggs are sold daily.

Efficient Hell Tour Route and Duration

Basic Information

• Duration: About 60 minutes (complete hell conquest)
• Walking Distance: About 1.2km
• Difficulty: Beginner (walking paths maintained)
• Best Season: Year-round (early morning/evening recommended)

Recommended Model Course

【Complete Conquest Course (60 minutes)】

Start: Onsen Shrine ↓ (5 minutes)

1. Daikyokan Jigoku (10-minute stay)

• Experience most intense steam
• Memorial photo at observation deck ↓ (5 minutes)

2. Oito Jigoku (15-minute stay)

• View legendary hell
• Rest at Unzen Hell Tea House
• Foot steaming experience ↓ (3 minutes)

3. Seishichi Jigoku (5-minute stay) ↓ (5 minutes)

4. Mud Volcano (10-minute stay)

• Observe cone-shaped natural phenomenon ↓ (7 minutes)

5. Christian Martyrdom Monument (10-minute stay)

• Historical learning and silent prayer ↓ (5 minutes)

6. Tour Other Small Hell Groups (15 minutes)

Goal: Onsen Shrine

Photography Best Spots

• Oito Jigoku stone wall end: Classic angle for tourist photos
• Daikyokan Jigoku observation deck: Most powerful steam
• Christian Martyrdom Monument: Historically significant memorial photos
• Machiko Rock: "Kimi no Na wa" movie location

Historical & Cultural Spots

Onsen Shrine (Unzen Jinja)

The oldest shrine in Nagasaki Prefecture, located at the northern end of Unzen Hell.

Historical Value:

• Founded: Taiho 1 (701) or earlier
• Head shrine of hot spring shrines within Shimabara Peninsula
• Base for mountain worship venerating Unzen-dake (Onsen-san)

Worship Recommendation: Traditional practice involves purifying mind and body by worshipping at Onsen Shrine before beginning hell tour exploration.

Machiko Rock

Memorial rock that became the filming location for the 1954 movie "Kimi no Na wa." The rock that heroine Kishi Keiko touched remains as a monument.

Stone Monument Words: "Forgetting means to forget completely; the sadness of a heart that cannot forget yet vows to forget."

Access, Fees & Operating Hours

Basic Information

• Operating Hours: 24-hour open (no lighting)
• Admission: Free
• Closed Days: None

Access Methods

Public Transportation

• 4-minute walk from Shimabara Railway Bus "Unzen" bus stop
• About 2 hours from Nagasaki Station

Automobile

• About 60 minutes from Nagasaki Expressway Isahaya IC
• About 1 hour 30 minutes from Kyushu Expressway Tosu JCT

Parking

• Onsen Shrine Parking: ¥500
• Manmyoji Parking: ¥500
• Multiple other private parking lots available

Surrounding Facilities

Unzen Hell Tea House

• Operating hours: 10:00-17:00
• Hot spring eggs, hot spring lemonade sales
• Full souvenir selection including Unzen beauty face masks

Seasonal Enjoyment

Spring (March-May)

• Miyama Kirishima blooming
• Christian Martyrdom Festival (3rd Sunday in May)
• Tourism season begins

Summer (June-August)

• Popular as summer resort
• Early morning walks recommended
• Mystical nighttime atmosphere

Autumn (September-November)

• Autumn foliage season
• Peak hot spring egg demand period
• Best tourism season

Winter (December-February)

• Contrast of snow scenery and hells
• Most beautiful season for steam
• Quiet atmosphere with few tourists

Frequently Asked Questions (FAQ)

Q: Can Unzen Hell be visited 24 hours anytime? A: Yes, it's open 24 hours with free admission. However, there's no nighttime lighting, so daytime visits are recommended for safety.

Q: Are there clothing considerations? A: Sulfur odor may adhere to clothing. Avoid favorite outfits and wear comfortable walking shoes.

Q: Can small children visit safely? A: Walking paths are maintained, but high-temperature steam emerges, so adults must accompany children and stay on designated paths.

Q: Are pets allowed? A: Due to high-temperature steam and sulfur gas, we recommend avoiding pet accompaniment for their health.

Q: Can it be enjoyed on rainy days? A: Rain makes steam more mystical while making footing slippery. Prepare rain gear and non-slip shoes.

Q: Are there photography restrictions? A: Photography is generally free, but consider other tourists. Especially around martyrdom monuments, maintain respectful photography.

Summary: Experience Nature's Wonder and Historical Weight at Unzen Hell

Unzen Hell is an unparalleled tourist destination where natural wonders created by over 30 diverse hells intersect with the heavy history of Christian martyrdom.

The power of geothermal activity where you feel Earth's breath, the tragedy of religious conflict 400 years ago, and hot spring culture inherited to modern times - all can be experienced in one place, unique to Unzen Hell.

In the luxurious environment of free 24-hour access, please take time to thoroughly enjoy hell touring. You'll surely feel both nature's greatness and history's weight simultaneously.

Basic Information

• Address: 320 Unzen, Obama-cho, Unzen City, Nagasaki Prefecture
• Operating Hours: 24-hour open
• Admission: Free
• Parking: Use surrounding paid parking (about ¥500)
• Contact: Unzen Onsen Tourism Association 0957-73-3434

Information in this article is current as of May 2025. Please check the official Unzen Onsen Tourism Association website for latest information.