Sulfur springs offer the quintessential onsen experience, with their unique aroma and milky white water. They provide a vivid and easily recognizable hot spring experience, which is the charm of sulfur springs.

What Are Sulfur Springs?

Sulfur springs are hot springs that contain a certain amount of sulfur. Specifically, they are classified as sulfur springs if they contain more than 2mg of total sulfur per kilogram of hot spring water.

Due to volcanic activity, sulfur from underground dissolves into the hot spring water, making sulfur springs abundant in volcanic Japan. They are a uniquely Japanese hot spring.

Appearance and Characteristics

Color: Milky white to greenish-white Smell: Sulfuric smell (similar to rotten eggs) Texture: Slippery and smooth pH: Slightly acidic to slightly alkaline

The distinctive smell is due to hydrogen sulfide gas. Often described as a "rotten egg smell," this is a characteristic aroma of sulfur springs.

Why Do They Turn Milky White?

Sulfur springs turn milky white because sulfur particles float in the water.

Freshly emerged sulfur springs are often clear. However, when exposed to air, sulfur precipitates, causing the water to turn milky white. This change is evidence that the sulfur spring is "alive."

Health Benefits of Sulfur Springs

Sulfur springs have strong antibacterial effects and vasodilatory actions.

Antibacterial Effect: Hydrogen sulfide kills bacteria, effective for chronic skin diseases, athlete's foot, and acne.

Vasodilatory Action: Hydrogen sulfide dilates blood vessels, improving blood circulation, beneficial for hypertension and arteriosclerosis.

Beautifying Effect: Removes dead skin cells, leaving the skin smooth.

Main Benefits

Common indications for sulfur springs include:

• Chronic skin diseases, atopic dermatitis
• Chronic gynecological disorders
• Diabetes, hypertension
• Arteriosclerosis
• Cuts, burns
• Neuralgia, muscle pain, joint pain

They are said to be effective for a wide range of symptoms.

Precautions

There are several precautions to take with sulfur springs.

Metal Accessories Discolor: Sulfur reacts with metals, causing them to turn black. Be sure to remove rings, necklaces, earrings, etc., before bathing.

Some May Dislike the Smell: The "rotten egg" smell is indeed unique. While you may get used to it, it might be surprising at first.

Strong Stimulation: Due to strong stimulation, those with sensitive skin should be cautious. Avoid long baths and rinse your body with fresh water afterward.

Photosensitivity: Some sulfur springs may have photosensitivity. It is recommended to avoid direct sunlight after bathing in such springs.

Notable Sulfur Springs

Kusatsu Onsen (Gunma Prefecture): One of Japan's top three onsen, famous for its highly acidic sulfur springs.

Noboribetsu Onsen (Hokkaido): A hot spring area offering nine types of spring qualities, rich in sulfur springs.

Hakone Onsen (Kanagawa Prefecture): A popular onsen area near Tokyo, known for the sulfur springs of Owakudani.

Unzen Onsen (Nagasaki Prefecture): Known for its "hell tours" and sulfur springs.

Recommended For

Those who want to enjoy a quintessential onsen experience, love milky white water, are not bothered by the sulfur smell, or suffer from chronic skin diseases. Sulfur springs offer the most authentic "I've come to an onsen!" feeling.

Conclusion

Sulfur springs are a unique feature of Japan's volcanic landscape. The milky white water and sulfur smell provide a distinct "I've come to an onsen!" experience.

Vivid and easily recognizable, sulfur springs are a special part of the onsen experience. Remember to remove metal accessories and enjoy the uniquely Japanese sulfur springs.