Daimaru Onsen (大丸温泉)

Introduction: The River of Steam at the Top of the Nasu World

Perched at a breathtaking 1,300 meters above sea level, at the very summit of the Nasu Onsen-kyo cluster, lies Daimaru Onsen (大丸温泉). This is not merely a bath; it is a geological marvel where a literal mountain river of steaming hot spring water is dammed to create massive, natural rock pools known as “Kawa-no-Yu” (The River Bath). Historically, this hidden spring was the beloved retreat of General Nogi Maresuke, a national hero of the Meiji era who visited annually for nearly a decade to heal his ailments. For the international traveler, Daimaru Onsen offers the ultimate “Wild Wellness” experience. Surrounded by alpine flora and the dramatic slopes of Mt. Chausu, you can submerge yourself in silky, metasilicic-rich waters while listening to the actual rush of the stream beneath you. It is a place where the boundaries between the Earth’s geothermal heat and the pristine mountain wilderness completely dissolve.

Key Information Table

The Healing Waters: The “River of Rejuvenation”

The water at Daimaru Onsen is unique for its sheer volume and purity. Unlike volcanic springs that require heavy dilution, Daimaru’s water flows at 800 liters per minute directly from the mountain source into the pools at its natural temperature.
The Beauty Component: The water is remarkably high in Metasilicic Acid, a natural skin-softening mineral that acts as a biological moisturizer. Balneologists refer to this as a “Silk Veil” that leaves the skin feeling exceptionally smooth.
The River Experience: The flagship Kawa-no-Yu consists of multiple tiered pools built directly into the riverbed. The steam rising from the flowing water provides a natural humidifying effect for the lungs, while the varying temperatures of the pools—cooled naturally by the mountain air—allow for a long, therapeutic soak even in the height of winter.

Top Recommended Stays: The Historical Anchor

• Daimaru Onsen Ryokan (大丸温泉旅館): The definitive place to stay. It features traditional Japanese rooms with wooden interiors and provides exclusive 24-hour access to the river baths. The ryokan also houses a museum-like display of General Nogi’s original diaries and clothing.
• Sanraku (Nasu Highland): A high-end luxury ryokan (100+ years history) nearby that uses the same pure source water. It offers a more refined, kaiseki-focused experience for those who prefer formal aesthetics.
• Hotel Epinard Nasu: A premier family resort in the valley that offers shuttle services to the upper Nasu peaks, making it a convenient “Base Camp” for those visiting Daimaru as a day trip.

Walking Guide & Scenic Spots: Volcanoes and Legends

Mt. Chausu (那須岳): Daimaru is the highest accessible point by road before the Nasu Ropeway. A 45-minute hike from the upper ropeway station takes you to the steaming crater of an active volcano.
Sessho-seki (Killing Stone): A volcanic site famous for the legend of the “Nine-Tailed Fox.” The stone split in two in 2022, creating a renewed interest in the area’s spiritual power.
Nasu Heisei-no-Mori: A former part of the Nasu Imperial Villa now open as a pristine forest park with well-maintained walking trails and bird-watching spots.

Local Gastronomy: General Nogi’s Sake and Highland Beef

Food in Daimaru is focused on the “Blessings of the Mountain.”
Nogi Shochu: A proprietary barley shochu made using the mineral-rich waters of the Daimaru source. It is aromatic and smooth, reflecting the stoic personality of General Nogi.
Tochigi Wagyu: The local ryokans serve premium A5-rank Tochigi beef, often prepared as *Shabu-shabu* to highlight the meat’s sweet fat.
Vegetarian/Vegan Survival:
穀菜茶房こと葉 (Kotoha): Located in central Nasu-machi (25-min drive), this is an all-organic, one-person operated vegan cafe serving beautiful seasonal plates.
Vegan Tip: Request the **”Sansai (Wild Vegetable) Tempura”** at the ryokan. Since Daimaru is far from the city, specify *No Fish Dashi* (Kombu-dashi only) at least 3 days in advance.[2, 3]

Cultural & Historical Context: The Stoic General

Daimaru’s identity is deeply linked to General Nogi Maresuke, who found peace here after the Russo-Japanese War. The local community preserves his spirit of “frugality and loyalty.” The third-generation owner of Daimaru Onsen Ryokan was even invited to serve as a student/servant at Nogi’s private residence in Tokyo because of the bond they formed at these springs. Visiting Daimaru is, for many Japanese, a pilgrimage to understand the soul of a historical “God of War” who sought healing in the silence of the peaks.

Practical Travel Tips for International Visitors

• Tattoo Policy: Daimaru Onsen Ryokan is relatively flexible for its Mixed Outdoor Baths. Bathers are provided with a large green wrap-around towel (Yuami-gi) that must be worn at all times, which naturally covers most tattoos.
• Cash & Payments: While the primary ryokan accepts credit cards, the nearby ropeway stalls and local buses are strictly cash-only.
• Connectivity: Wi-Fi is available in the main lobby and newer annex rooms, but mobile signals can be unstable due to the sheer rock walls of the canyon.

2025-2026 Latest Updates

2026 Winter Access: Due to heavy snowfall at 1,300m, the road above Daimaru to the Ropeway will be CLOSED from early December 2025 to mid-March 2026. Specialized snow-tire shuttles will operate for ryokan guests during this period.
Renovation: The historic annex “Bekkwan” has been updated in 2025 with new forest-view meditation decks.

Safety & Manners

Mixed Bathing Etiquette: Always wear the provided wrap-around towel in the gender-mixed River Bath. Do not enter the water naked in these zones. Also, do not use soap or shampoo in the river pools to protect the downstream environment.
Weather: At 1,300m, the temperature is 10°C lower than the plains. Even in summer, bring a windbreaker or light jacket.