Shikotsuko Ito Onsen (支笏湖いとう温泉)

Introduction: The Legendary “Blue Secret” Hidden on the Shores of Lake Shikotsu

Deep on the rugged northern shore of Lake Shikotsu—Japan’s clearest and second-deepest caldera lake—lies the ghost of a thermal legend: Shikotsuko Ito Onsen (支笏湖いとう温泉). Once celebrated as one of the “Three Great Hidden Springs of Japan,” this destination has achieved a mythical status among onsen purists. While the main Shikotsuko resort area bustles with day-trippers, Ito Onsen offers a profound encounter with the raw, unrefined beauty of the “Shikotsu Blue” wilderness. For the international traveler and serious “Onsen Hunter,” Shikotsuko Ito Onsen represents the ultimate “Lost Frontier.” It is a place where the thermal water flows directly from the lakebed into stone basins, where the air is scented with primeval spruce, and where the boundary between human architecture and the volcanic earth has almost entirely dissolved. Though the original lodge is currently in a state of quiet preservation, the site remains a spiritual pilgrimage point for those seeking the true soul of Hokkaido’s hidden history.

It’s close to Sapporo, and there are hot springs right by the lake with breathtaking views. I also highly recommend a route that ends with indulging in the amazing food at New Chitose Airport before you fly out.

Key Information Table

The Healing Waters: The “Mirror Lake” Mineral Surge

The water at Shikotsuko Ito Onsen is geologically unique within the Shikotsu-Toya National Park. It is a powerful Sodium-Chloride / Bicarbonate / Sulfate Spring.
The Natural Phenomenon: Unlike standard resort onsens, the water here bubbles up naturally from the gravel bottom of the tubs, which are built at the same level as Lake Shikotsu. This means the depth of the bath fluctuates with the lake’s water level—a phenomenon found in only a few places in Japan.
The Sensation: The water is clear but carries a faint amber tint and a complex earthy aroma. The bicarbonate content acts as a natural cleanser, gently exfoliating the skin, while the salt and sulfate ions provide a deep, penetrating warmth that matches the intensity of the volcanic caldera. To soak here is to feel the weightless “Mirror Lake” effect, as if your body is merging with the deep blue depths of Shikotsu itself.

Top Recommended Bases & Logistics

Since the original Ito Onsen lodge is currently closed for standard business, travelers use the neighboring lakeside hubs as their base camp.

• Marukoma Onsen Ryokan: Located just a few kilometers away on the same northern shore. This historic ryokan shares similar water qualities and is the most logical base for those wanting to explore the Ito Onsen heritage site.
• Shikotsuko Tsuruga Resort Spa Mizu no Uta: A 5-star luxury resort located in the main village (30 mins away). Ideal for international travelers who want world-class amenities while making a day-expedition to the northern “secret” spots.
• Poropinai Campground: For budget-conscious adventurers and “Van-life” travelers, this nearby campground offers the most direct access to the lake’s wild northern stretches.
• Chitose City Hotels: Many travelers stay near New Chitose Airport and rent a 4WD vehicle for a daytime exploration of the northern shore.

Must-Visit Neighborhood Spots: Blue Ponds and Volcanoes

Poropinai Beach: A stunning beach area near the onsen, popular for lake photography and watching the sunrise over Mt. Eniwa.
Mt. Eniwa Hiking Trail: The trailhead starts near the northern access road. A challenging climb that rewards hikers with a panoramic view of the “Shikotsu Blue” lake.
The Underwater Forest: Take a glass-bottom boat tour from the main Shikotsuko village to see the submerged volcanic formations and submerged trees that have been preserved by the lake’s near-freezing purity.

Local Gastronomy: The Legend of the Himemasu

Food in this region is defined by the absolute clarity of the lake water.
Himemasu (Kokanee Salmon): This freshwater salmon is native to Lake Shikotsu. Try it as “Ruibe” (traditional frozen sashimi) or salt-grilled at the local minshukus in Poropinai.
Vegetarian/Vegan Survival:
For Vegans: This area is a major producer of Hokkaido Soybeans and Corn. At the luxury resorts in the main village, you can request a “Shojin” or vegetable-only course. In the summer, fresh local corn sold at the lakeside stalls is 100% vegan and incredibly sweet. The local **”Shikotsu Milk”** is also highly prized for vegetarians.

Cultural & Historical Context

The name “Ito” honors the founding family who established the lodge in the early 20th century. For decades, it was a sanctuary for explorers, scientists, and those suffering from chronic illnesses who sought the medicinal power of the lake-level springs. The architecture of the original baths—wooden tubs carved into the shore—represented the peak of Japan’s “Harmonious Volcanism.” Today, it stands as a monument to Hokkaido’s pioneering era, where survival and thermal beauty were inextricably linked.

Practical Travel Tips for International Visitors

• Status Check: **CRITICAL.** Shikotsuko Ito Onsen has been closed for overnight stays for several years. However, the site and its natural surroundings are often accessible for hiking and photography. Always check the latest road status (Route 453) at the Shikotsuko Visitor Center before departing.
• Tattoo Policy: While the site is a “historical ruin/secret spot,” the nearby active resorts (Marukoma, Tsuruga) are among the most **tattoo-friendly** in Hokkaido due to their international clientele.
• Transportation: A **rental car is absolutely mandatory**. There is no public bus service to the northern shore. The forest road is narrow and prone to falling rocks—drive with extreme caution.
• Cash Only: If you visit the local seafood shacks in Poropinai, they are **strictly cash-only (JPY)**. Withdraw money at the airport or in Chitose city.

2025-2026 Latest Updates

In 2025, a new “Heritage Trekking Guide” was launched in English by the Chitose Tourism Board, providing digital maps and historical context for the Ito Onsen site. For the 2026 season, local enthusiasts are planning a “Small-scale Coastal Cleanup,” inviting travelers to help preserve the pristine “Blue Mirror” environment in exchange for a guided history talk.

Safety & Manners

When visiting the Ito Onsen site, never enter restricted structures; the historic buildings are delicate and potentially unstable. Respect the wildlife—Ezo deer and Northern Foxes are common; **do not feed them**. Always carry a bear bell if you are walking the northern shore trails. Finally, respect the silence; this area is a place of deep spiritual importance to the local community.