Shiraoi Onsen (白老温泉)

Shiraoi Onsen: Diving into the Moor Springs and Ancient Soul of the Ainu

Located on the scenic Pacific coast of Hokkaido, Shiraoi Onsen is a destination where the geological history of the Earth meets the living heritage of Japan’s indigenous people. Known for its rare Moor (Plant-Derived) Springs, Shiraoi offers a “botanical” hot spring experience that is virtually unique to Hokkaido. This amber-colored water, rich in prehistoric plant minerals, is often called “Liquid Beauty” for its extraordinary skin-moisturizing properties. Since 2020, Shiraoi has gained global significance as the home of Upopoy (The National Ainu Museum and Park), a magnificent facility dedicated to the revival of Ainu culture. Shiraoi Onsen provides a sophisticated blend of maritime beauty, high-end resort luxury, and deep cultural immersion, making it a mandatory stop for travelers seeking to understand the true roots of northern Japan.

Key Information

The Healing Waters: The Science of the Moor and “Liquid Beauty”

The waters of Shiraoi are geologically distinct from the sulfurous springs of nearby Noboribetsu. These are Moor springs, formed from organic humic substances produced by the underground carbonization of ancient plants. Scientifically, the water is an alkaline sodium bicarbonate saline spring, characterized by its tea-brown hue and a silky, viscous texture. The organic compounds act as a natural cosmetic lotion, gently exfoliating dead skin cells while providing deep hydration—earning it the title of “Bihaku-no-yu” (Whitening Bath). Furthermore, the salt content forms a mineral film on the skin that traps body heat, making it exceptionally effective for warming the body’s core. Because the湯量 (water volume) is so high in Shiraoi, most facilities use 100% natural, free-flowing water (Gensen Kakenagashi).

Top 5 Recommended Ryokans

• Hoshino Resorts KAI Poroto (Ultra-Luxury/Design): An architectural masterpiece set directly on the banks of Lake Poroto. The “Koshi-no-yu” bath features a cone-shaped structure inspired by traditional Ainu architecture, offering a high-end conceptual experience.
• Kokoro no Resort Umi no Bettei Furukawa (Luxury/Ocean View): Perched on a cliff overlooking the Pacific Ocean, this resort emphasizes “meditation and views.” It features an infinity outdoor bath and is highly rated for its peaceful, adult-only atmosphere.
• Kojohama Spa Hotel (Renovated Heritage): A cornerstone of the town that underwent major renovations in 2024. It offers spacious family rooms and a massive bathing complex that uses three distinct spring sources.
• Hotel Izumi (Scenic/Value): Located on a hill, this hotel is famous for its panoramic open-air baths and its connected “Park Golf” course, providing a high-quality stay at an affordable price.
Hostel Haku (Budget/Cultural): A stylish, modern hostel located in central Shiraoi, perfect for younger travelers wanting to explore Upopoy and the local cafes on a budget.

Must-Visit Public Baths (Soto-yu)

Shiraoi is a paradise for day-trip bathers. The “Yumeguri” (Bath Hopping) culture is strong here. The Kojohama Onsen Sento facilities scattered along Route 36 offer a local, retro experience where you can soak in authentic moor water for just 500 yen alongside the town’s fishermen. For those seeking a higher-end day bath, Hoshino Resorts KAI Poroto offers limited day-trip access to their designer pools (booking recommended). Additionally, the free Public Footbath at Upopoy (Poroto Mintar) allows you to warm your feet while surrounded by Ainu woodcarvings and handicrafts.

Walking Guide & Scenic Spots

Start with a visit to Upopoy (The National Ainu Museum and Park). This is Hokkaido’s most important cultural site, featuring a reconstructed village (Kotan), world-class museum exhibits, and traditional dance performances. Next, walk along the Lake Poroto Forest Path, a peaceful trail through primeval forest that reflects in the lake’s clear waters. For nature lovers, head to Lake Kuttara, which has some of the clearest water in Japan and is surrounded by primary forests that turn brilliant red in autumn. In winter, the lake surface becomes a silent world of snow, perfect for snowshoeing tours.

Local Gastronomy & Souvenirs

Shiraoi is world-famous for its Shiraoi Wagyu Beef. This high-grade beef is known for its fine marbling and deep flavor—try it as a steak or in a “Banto-don” bowl. Another local specialty is Hokkaido Salmon, which is harvested in large volumes at the local river mouths. For souvenirs, look for Ainu Woodcarvings (especially the iconic owls) and original Tarako (Cod Roe) products from the neighboring Kojohama market. Don’t miss the Ainu-motif apparel and stationery from the gift shops at Upopoy.

Cultural & Historical Context

The name Shiraoi comes from the Ainu word sir-au-i, meaning “a place of many horseflies.” Historically, Shiraoi was the site of a major Ainu settlement and later became a pioneering hub for fishing and forestry. The establishment of Upopoy in 2020 was a landmark moment for Japan, recognizing the Ainu as an indigenous people and creating a space for “ethnic harmony.” This connection between the geothermal moor springs—seen by the Ainu as “The Breath of the Earth”—and the ancient forest wisdom is what makes Shiraoi a unique “Power Spot” in central Hokkaido.

Practical Travel Tips

Transportation: Shiraoi Station is a major stop for the “Hokuto” Limited Express; from the station, Upopoy is just a 10-minute walk. Booking: For KAI Poroto and Umi no Bettei Furukawa, booking at least 5-6 months in advance is highly recommended. Seasonality: Summer is best for Upopoy outdoor events; autumn (October) for foliage; and winter for “Yukimiburo” (snow-view bathing). Cash: Small traditional ryokans and museums often only accept Japanese Yen; ensure you have enough on hand before leaving central Sapporo.

2025-2026 Latest Updates

In April 2026, Hokkaido Prefecture will introduce a new tiered accommodation tax (100–500 yen per night), which will be used to fund regional tourism infrastructure. Additionally, Upopoy has announced an expanded schedule for its “Traditional Ainu Food Fair” for the 2025 summer season. A new multilingual AI-guide system was installed at the Shiraoi Visitor Center in late 2024 to provide deeper insights into the town’s history for international guests.

Safety & Manners

In the onsen, always rinse thoroughly before entering the communal tub to maintain the mineral integrity of the moor water. When visiting Upopoy, please remember that the traditional houses (cise) are sacred reconstructions; do not touch the interior artifacts unless invited by a guide. Finally, Shiraoi is a quiet seaside town; please maintain a quiet tone during your evening walks through the residential streets and take all trash back to your hotel.