Unzen Jigoku (Unzen Hells)

Unzen Jigoku, the 'Hells of Unzen', is a dramatic geothermal field high in the volcanic mountains of the Shimabara Peninsula in southeastern Nagasaki Prefecture. Here the earth hisses and steams: some thirty vents and pools bubble with sulphurous, mineral-laden water and gas, sending up billowing clouds of white steam that drift across a barren, otherworldly landscape of pale, scorched rock. A network of boardwalks and paved paths threads through the field, letting visitors walk right among the roaring fumaroles and steaming ground, an experience both spectacular and, thanks to the smell of sulphur and the heat rising underfoot, unforgettable.

The hells sit within Unzen, which in 1934 was designated Japan's very first national park, and the area has been a celebrated hot-spring resort since the Meiji period, drawing not only Japanese visitors but foreign residents of nearby treaty ports escaping the summer heat. The name 'jigoku' reflects a darker history too: during the persecution of Christians in the seventeenth century, the scalding pools of Unzen were used as a place of torture and execution for those who would not renounce their faith, and small markers along the trails commemorate the martyrs. This layer of history gives the steaming ground a sombre resonance beneath its natural drama.

Walking the loop through the field takes around an hour at an easy pace, following well-made paths with railings that keep visitors safely back from the hottest vents. Interpretive signs explain the geology and history, and viewpoints let you take in the whole steaming basin ringed by forested slopes. A cheerful counterpoint to the infernal scenery comes from the stalls that sell onsen tamago, eggs slow-cooked in the geothermal steam until the yolks turn rich and creamy, a classic treat you can eat warm as you stroll. Shops also sell local sweets and crafts flavoured or coloured with the local minerals.

Unzen Onsen, the small hot-spring town surrounding the hells, makes a comfortable base, with ryokan and public baths fed by the same volcanic waters, and the surrounding national park offers hiking, autumn foliage, and, higher up, the peaks of the Unzen volcano complex. Autumn brings brilliant colour to the highland forests, while winter can dust the area with snow and rime ice, and spring and summer offer cool mountain air well above the coastal heat. The hells themselves are free and open at all times, with restrooms and shops in the adjacent town.

Getting to Unzen Jigoku requires a mountain journey but is well worth it. From Nagasaki, take a train to Isahaya, then a bus that climbs for around eighty minutes up onto the Shimabara Peninsula to Unzen Onsen; the hells are right in the town. Drivers will find the ascent scenic, and the area combines naturally with the Unzen ropeway and Mount Fugen for hiking, and with the historic town of Shimabara and its castle down on the coast. For travellers exploring beyond Nagasaki city, the steaming, sulphurous, history-laden Hells of Unzen are one of the most memorable natural sights in all of Kyushu.