Oniishi Bozu Jigoku stands apart within Beppu’s famous Jigoku Meguri for its striking sensory contrasts. Rather than bright colors, this “Hell” presents calm, monochrome pools of thick grey mud that boil at nearly 99°C (210°F). Because the mud is highly viscous, steam becomes trapped beneath the surface, pushing the clay upward into perfectly rounded domes. When they burst, they resemble the shaved heads of Buddhist monks, giving rise to the name “Bozu.” The sound they produce is a soft, rhythmic “plop,” which, combined with the gentle motion of the mud, creates an unexpectedly meditative atmosphere. This peaceful visual effect stands in sharp contrast to the intense heat beneath the surface and to the violent imagery often associated with the word “Hell.”

The name becomes even more poetic when considering its origins: Oniishi, meaning “Demon Stone,” is the name of the district where the hell is located. This makes the full name feel almost mythical—“The Monk’s Head of the Demon Stone District”—blending spiritual symbolism with local geology.

Historically, Oniishi Bozu Jigoku is one of the oldest documented geothermal sites in Beppu. It appears in the Bungo Fudoki, a regional chronicle compiled in 733 AD, during the Nara Period. For ancient communities, the violent bursts of boiling mud rendered the area too dangerous for agriculture, strengthening the perception that these geothermal zones were the dwelling places of spirits or demons—hence the term “Jigoku” (Hell). A local legend adds further color, claiming that a demon once hurled a massive stone to create this spring.

After being closed for nearly 40 years, the site underwent a major renovation and reopened in 2002, combining modern walkways with traditional landscaping. Visitors today stroll through beautifully maintained gardens, accented by cedar pathways and soft greenery. Another distinctive feature is Oni no Takaibiki, or “The Demon’s Snoring,” a steam vent that emits a deep, rumbling pulse believed to resemble a slumbering demon breathing beneath the earth.

A particularly unique advantage of this site is its connection to Oniishi no Yu, a full public bathhouse fed by the same geothermal source. Visitors may enjoy the complimentary foot bath near the entrance, or pay a separate fee to bathe in mineral-rich waters inside the bathhouse, which features indoor cedar baths and open-air rotenburo on the upper level overlooking the gardens.

Many travelers visit Oniishi Bozu Jigoku together with its neighbor, Umi Jigoku. The contrast is visually striking: Umi Jigoku’s deep cobalt-blue pool versus Oniishi’s calm, monochrome grey mud, offering one of the most dramatic side-by-side geothermal comparisons in Beppu.

All 7 Hell Ponds (Jigoku Meguri Set):

• Umi Jigoku — cobalt-blue hot spring
• Chinoike Jigoku — red mineral pond
• Shiraike Jigoku — milky-white pond
• Kamado Jigoku — multi-stage hot springs
• Oniishibozu Jigoku — bubbling mud pools
• Oniyama Jigoku — Crocodile-breeding hot spring
• Tatsumaki Jigoku — natural erupting geyser

• From Beppu Station, take a bus bound for the Kannawa Onsen area and get off at the Oniishi Bozu Jigoku stop, which is only a short walk from the entrance. Travelers driving by car will find clear signage throughout Beppu directing them to the Jigoku Meguri locations, and parking is available onsite.

• Morning visits offer a quieter atmosphere and excellent visibility of the mud domes.
• Pair your visit with nearby Umi Jigoku to appreciate the dramatic differences in color and texture between the two hells.
• Wear comfortable shoes, as the grounds involve outdoor paths, and
• consider scheduling time to enjoy the Oniishi no Yu bathhouse afterward for a relaxing contrast to the intense geothermal scenery.

Admission Fee:

• Single Entry: 500 JPY (Adults) / 250 JPY (Children).
• Jigoku Meguri Pass: 2,400 JPY (Adults) / 1,200 JPY (Children).

Note: The Jigoku Meguri Pass allows one-time entry to all 7 official “Hells” and is valid for two consecutive days.

Opening Time:

• Open daily from 8:00 AM to 5:00 PM.