Marukoma Onsen (丸駒温泉)

Introduction: The Century-Old Secret Hidden on the Shores of Lake Shikotsu

While Lake Shikotsu is known for its incredible clarity and deep blue waters, most visitors only see the eastern tourist village. However, on the rugged, undeveloped northern shore lies Marukoma Onsen (丸駒温泉). Established in 1915, Marukoma is one of Hokkaido’s most historic and unique “secluded” hot springs (Hitoh). It is a destination that feels like a time capsule, where the hot spring tubs are directly connected to the natural water levels of Lake Shikotsu. For international travelers seeking a profound sense of isolation, historical grandeur, and a connection to the raw elements of nature, Marukoma is an essential pilgrimage. Accessible only by a winding forest road or a rare boat trip, this is where you go to witness the sun rise over the lake while submerged in waters that have been flowing for over a hundred years.

Key Information Table

Address	〒066-0287 北海道千歳市幌美内7番地 / 7 Poropinai, Chitose-shi, Hokkaido
Google Maps	View on Google Maps
Mapcode for GPS	708 724 532*44 (Crucial for the long, winding access road)
Spring Quality	Sodium-Chloride / Bicarbonate / Sulfate Spring
Benefits	Neuralgia, joint pain, relief from cold sensitivity, and deep skin moisturization.
Access	Approximately 60 minutes from New Chitose Airport by car. A shuttle bus runs from Lake Shikotsu bus terminal (reservation required).
Number of Ryokans	1 landmark inn: “Marukoma Onsen Ryokan” (Traditional and historic).
Day-trip Bathing	Available 10:00 – 15:00. Fee: 1,000 JPY (Adults).

The Healing Waters: The Natural Lake-Level Phenomenon

What makes Marukoma Onsen world-famous is its Natural Open-Air Bath. This historic tub is carved directly into the rocky shoreline and is separated from Lake Shikotsu only by a stone wall. Most remarkably, the water level in the bath fluctuates naturally with the level of the lake. In some years, the water might be waist-deep; in others, it might be shallow enough to sit on the smooth stones. The temperature is regulated by the natural flow of the spring from the bottom of the tub. The spring is a Sodium-Chloride / Sulfate mix, known for its “rejuvenating” properties. The water is slightly cloudy with minerals, providing a sense of privacy even in the open air. Soaking here, with the sound of the lake waves lapping just inches away, is a spiritual experience that transcends typical hot spring visits.

Top Recommended Stays & Bases

• Marukoma Onsen Ryokan (The Original): The only place to stay if you want the full experience. The rooms are traditional Japanese style, many with breathtaking views of the lake. The dinner service features “Irori” (hearth) cooking, adding to the nostalgic atmosphere.
• Shikotsuko Tsuruga Resort Spa Mizu no Uta: Located in the main village (30 mins away), this is a luxury option for those who want five-star amenities but plan to visit Marukoma as a day trip.
• Lake Shikotsu Tsuruga Bessou Ao no Za: The peak of luxury in the area, offering private in-room onsens with views of the caldera lake.
• Poropinai Campground: For budget travelers, this nearby campground offers a rugged outdoor experience. You can camp by the water and drive to Marukoma for your daily bath.

Must-Visit Public Baths & Facilities

Marukoma is a single-ryokan destination, but its facilities are extensive.

The Panoramic Rotenburo

In addition to the lake-level natural bath, there is a modern outdoor bath perched higher on the hillside. This tub offers a wide-angle, cinematic view of the entire Lake Shikotsu caldera and the majestic Mt. Eniwa. It is the best spot for photography (before the bath opens to others!).

Walking Guide & Scenic Spots

Mt. Eniwa Hiking Trail: The trailhead is located near the onsen. It is a challenging climb but offers the most spectacular view of the “Shikotsu Blue” lake from above.
The Underwater Forest: Because the lake is so clear (consistently ranked #1 in Japan), you can take a glass-bottom boat from the main village to see the submerged trees and volcanic rock formations.
Shikotsu-Toya National Park Boardwalks: Gentle paths wind through the forests surrounding the lake, perfect for birdwatching and seeing Ezo deer.

Local Gastronomy: The Himemasu (Kokanee Salmon)

The culinary pride of Lake Shikotsu is the Himemasu. This freshwater salmon is native to the cold, deep waters of the lake.

• Himemasu Sugata-yaki: Whole grilled salmon with a dash of sea salt. The meat is sweet, fatty, and tender.
• Himemasu Sashimi: Because the lake water is so clean, the raw fish is incredibly crisp and refreshing.
• Local Wild Vegetables (Sansai): In spring, the chefs at Marukoma harvest bamboo shoots and fiddlehead ferns from the surrounding mountains.

Cultural & Historical Context

Marukoma Onsen was founded by the first-generation owner, Kamekichi Satomi, who recognized the quality of the water while exploring the lake by boat. For decades, the only way to reach the onsen was by water, earning it the reputation of a “secret getaway” for writers, artists, and political figures seeking peace. The ryokan has survived major eruptions and harsh winters, standing as a testament to the “Pioneer Spirit” of Hokkaido. Today, the fourth generation of the Satomi family continues to guard the fires and the springs.

Practical Travel Tips for International Visitors

• Transportation: A rental car is the most reliable way to reach Marukoma. The forest road is narrow and can be snowy. If using the shuttle bus, you must book it at least 2 days in advance.
• Tattoo Policy: Marukoma is more traditional and historic. Small tattoos should be covered. For large tattoos, consider booking a room with a private indoor bath to ensure you can soak comfortably.
• Cash & Payments: The ryokan accepts credit cards (Visa/Mastercard), but if you are visiting for a day-trip bath or using the small shop, have cash (JPY) ready.
• Airport Proximity: Marukoma is surprisingly close to New Chitose Airport. It is a much better “first night in Japan” experience than a city hotel.

2025-2026 Latest Updates

In late 2025, Marukoma completed a renovation of its lake-view dining hall, adding large floor-to-ceiling windows to enhance the “infinity” feel. They have also introduced a “Night Stargazing Onsen” program, where all outdoor lights are dimmed at 10:00 PM to allow guests to see the Milky Way from the tubs.

Safety & Manners

The natural lake-level bath has a floor of natural river stones and can be uneven; please walk carefully. Lake Shikotsu is extremely deep and cold; never attempt to swim directly from the onsen into the lake. In the ryokan, please respect the quiet atmosphere, especially in the historic corridors. Following the “Moku-yoku” (silent bathing) trend is encouraged here to fully appreciate the sounds of the lake and forest.