Stolbovskaya Eco-Trail to Mud-Spring Lechebnitsa — Kuril Geothermal Wilderness

A contained loop through Kuril old-growth and onto a live volcanic terrace: the Stolbovskaya trail to Lechebnitsa is Kunashir's most atmospheric geothermal excursion — shorter than the cape-column day, stranger in every way.

What Lechebnitsa is

Lechebnitsa (lechebnitsa — "sanatorium" or "therapeutic site") is a cluster of natural mud pools and steam vents on the lower eastern flank of Mendeleev Volcano (1 125 m), the dominant geothermal feature of southern Kunashir. The volcano is classified as active and has shown increased fumarolic activity in recent decades; the eastern flank is the sector the Kurilsky Nature Reserve permits public access to, via a boardwalk built and maintained by reserve staff.

The pools at Lechebnitsa are true mud volcanoes in miniature: groundwater heated by the underlying magmatic system dissolves volcanic rock into a grey-blue siliceous slurry that rises and collapses in slow bubbles 20 to 40 cm across. Steam vents alongside hiss intermittently, depositing yellow sulphur crystals around their rims. The ground immediately adjacent is warm to the touch, and in the right weather — overcast, still — the entire terrace sits in a low cloud of its own making. A boardwalk circuit of roughly 400 metres allows close approach without disturbing the crust.

The medicinal reputation of the site predates its reserve status: local tradition holds the thermal muds to have skin-healing properties, and early Soviet-era field reports used the "therapeutic" name. The boardwalk now keeps visitors off the active ground, though the warm-spring pool downstream of the main field remains accessible for wading.

The trail

The Stolbovskaya trailhead is on the eastern perimeter of Mendeleev Volcano, accessible from Yuzhnoye Kurilskoye by 4x4 in 30 to 45 minutes. The path ascends gently through old-growth Sakhalin fir and Kuril bamboo, gaining perhaps 150 to 200 metres of elevation over roughly four to five kilometres. The understorey is dense — Petasites japonicus leaves broad enough to shelter under, ferns to waist height — and the light through the canopy shifts from green to grey as the forest opens onto the volcanic terrace. Approach boardwalk sections begin roughly 300 metres before the main field.

We spend 60 to 90 minutes in the active zone — time enough to walk the full boardwalk circuit, observe the bubble cycles, and listen to the vent pressure change. The descent follows the same route, arriving at the trailhead in early afternoon. This leaves time, on a combined day, for the coastal hot-spring pool at Stolbovskoye before the return drive.

Practical notes

• Base: Yuzhnoye Kurilskoye, Kunashir. This excursion pairs well with the Cape Stolbchaty trail as back-to-back day options on a multi-day Kunashir programme.
• Permits: Kunashir is a border-control zone; Mendeleev Volcano's reserve zone requires a Kurilsky Nature Reserve entry permit. AMIST handles both — allow 2–3 weeks minimum. Foreign nationals require additional processing time.
• Getting to Kunashir: 90-minute flight Yuzhno-Sakhalinsk → Mendeleyevo Airport (DEE), or seasonal ferry. AMIST coordinates both options.
• Trail distance and difficulty: approximately 8–10 km round trip, moderate elevation gain (150–200 m), sections of boardwalk over hydrothermal ground. Suitable for most walkers; no technical skill required.
• Season: late June – mid-September. The mud pools are most active in July and August; morning visits see the best steam display before the day warms.
• Safety: do not leave the boardwalk in the active zone — the hydrothermal crust is thin and the mud beneath scalding. Our guide enforces boardwalk discipline strictly.
• What to bring: waterproof boots (some sections are muddy regardless of weather), windproof shell, light gloves (the vent area is cooler than ambient at the rim), 1.5 litres of water.
• Included: 4x4 transfer from Yuzhnoye Kurilskoye, certified Kurilsky Reserve guide, entry permits, packed snack.
• Not included: flights and ferry to/from Kunashir, accommodation, full meals (bring your own lunch for the full-day combined version).

Why AMIST guides this trail

Lechebnitsa is the kind of place that does not photograph well and is entirely irreplaceable in person: the sound of the mud collapsing under its own weight, the warmth coming through the boards underfoot, the sulphur on the back of the throat. It takes about twenty minutes to stop bracing for something dramatic and simply stand on a planet that is still forming. AMIST has been guiding on Kunashir since the early 2000s, and our guides hold Kurilsky Reserve certification — a requirement for entry to the active volcano zone, not a formality. We run groups of six or fewer, and we time the visit for the morning window when the vents are most expressive and the boardwalk is empty.