Phia Oắc National Park: A Moss-Covered Wonderland of Ice and Mist in Cao Bằng, Vietnam

If you’re drawn to pristine forests and untrodden trails, Phia Oắc National Park (part of the Phia Oắc – Phia Đén National Park complex in Nguyên Bình District, Cao Bằng Province) will captivate you from the very first step. At an elevation crowned by Phia Oắc Peak (1,931 m), this area enjoys a cool climate year-round. In winter, temperatures sometimes drop below 0°C, creating layers of frost and ice over the moss and lichens — a sight rarely seen in Vietnam. The dense evergreen subtropical forest, cloaked in emerald moss and drifting mist, feels like a journey into a fairytale realm.

This ExoTrails guide brings you everything you need: the best travel season, how to get there, a 2-day-1-night itinerary, trekking and cloud-hunting routes, food and lodging tips, essential gear checklist, safety and conservation notes, and downloadable locations to save in the app for your adventure.

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Quick overview: Phia Oắc – Phia Đén National Park “at a Glance”

• Location: ~70–75 km west of Cao Bằng City via TL212 – QL34
• Terrain: mountain ranges with peaks like Phia Oắc and Phia Đén, dense forests, streams, and misty valleys
• Ecosystem: moist evergreen forest; rich in moss and lichen species; outstanding biodiversity with many rare species
• Top Experiences: moss forest trekking, conquering Phia Oắc Peak, winter frost hunting, strolling the French colonial ruins around Tĩnh Túc, combining with the Cao Bằng – Non Nước scenic route
• Best for: travelers with moderate fitness (short moss trails) to intermediate trekkers (Phia Oắc summit route – steep and medium-length)

Why Phia Oắc – Phia Đén leaves a lasting impression

Winter Frost: Not every year brings ice, but when temperatures in Phia Oắc National Park drop below freezing, the forest dons a shimmering coat of frost — like a miniature Northern Europe. It’s a once-in-a-lifetime moment for ice chasers and nature enthusiasts alike.

The “Green Velvet” Moss Forest: Thick moss carpets, tree trunks and rocks; sunlight filters through the canopy, painting shades of jade and emerald that fascinate photographers.

Quiet Trails: Compared to northern Vietnam’s crowded destinations, Phia Oắc National Park remains a tranquil escape, a place where you can hear rustling leaves, murmuring streams, and even the gentle rhythm of your own heartbeat.

Historical Echoes: Scattered French colonial buildings from the Tĩnh Túc tin-mining era add nostalgic stops amid the wilderness.

Gateway to More Adventures: Easily combined with Bản Giốc Waterfall, Pác Bó Historical Site, or Thang Hen Lake for extended itineraries.

When to go – Timing is half the experience

• Dry Season (Oct–Apr): At Phia Oắc National Park, clear skies and minimal rain make it the perfect season for summiting and cloud hunting. From December to February, frost may blanket the landscape during strong cold fronts. Be ready for sub-zero temperatures with thermal layers, gloves, and windproof, waterproof clothing.
• Rainy Season (May–Sep): The forest turns lush green and misty. Perfect for short moss treks and macro photography, but trails can be slippery, avoiding summiting during storms.
  Pro tip: If frost is your goal, track cold-wave forecasts in Northeast Vietnam. When Cao Bằng City drops below 5–7°C, Phia Oắc’s high ridges may hit freezing.

Getting there – Safe and smart travel

Getting to Phia Oắc National Park is an adventure in itself, offering scenic mountain roads and breathtaking views along the way. Whether you travel by bus, motorbike, or car, the journey sets the tone for the wild beauty awaiting you in Cao Bằng’s highlands.

From Hanoi → Cao Bằng:

• Sleeper bus/limousine: 6–7 hours (overnight for convenience).
• Self-drive/motorbike: via QL3 – mountainous route, best done in daylight with rest stops.

From Cao Bằng → Phia Oắc – Phia Đén:

• Follow TL212 → QL34 westward for about 70–75 km. Mountain passes are winding, with narrow sections — fuel up early, bring snacks and water.
• Trailheads: vary by route. Moss forest trails usually start with a short dirt road before trekking. The Phia Oắc summit route is steeper and longer.

Safety notes: check brakes, tires, and headlights before departure. Fog reduces night visibility — drive cautiously.

Recommended routes by difficulty

For those eager to explore beyond the beaten path, Phia Oắc National Park offers trails for every kind of adventurer, from misty moss forests to challenging mountain summits. Each route reveals a different side of the park’s magic, blending raw nature, crisp mountain air, and a quiet sense of discovery.

(Difficulty may vary depending on fitness, weather, and trail condition. Always go in groups of 3+, inform someone of your plan, and save offline maps in ExoTrails.)

Moss Forest Trail – Step into a Green Library

• Duration: 2–4 hours round trip
• Difficulty: Easy to Moderate (humid forest path, slippery roots and rocks)
• Highlights: thick moss, ancient trees, and magical filtered light. In winter, mist and frost create dreamlike photo effects.

Conquer Phia Oắc Peak (1,931 m)

• Duration: 1 day (early start) or 2D1N for camping and sunrise/cloud-sea hunting (camp only in designated areas).
• Difficulty: Moderate to Hard (long steep sections; cold winds at altitude).
• Highlights: 360° panoramic views, rocky ridgelines, frost or ice crystals in winter.
• Gear: trekking poles, grippy shoes, windproof jacket, wool hat. Check weather forecasts and avoid windy hours.

Tĩnh Túc Town Walk – French Heritage Vibes

• Duration: half to full day.
• Pace: easy sightseeing through colonial villas and buildings reminiscent of the old mining era. Enjoy a local lunch or a slow coffee break.

Suggested 2-day-1-night itinerary (Perfect for beginners to intermediate travelers)

Day 0 (Evening): Overnight bus from Hanoi to Cao Bằng.

Day 1:

• Morning: Cao Bằng → Phia Oắc – Phia Đén. Stop for roadside viewpoints. Check in to a homestay or guesthouse nearby.
• Noon–Afternoon: Trek the moss forest (2–4 hours). Take photos, rest in the forest — stay warm and avoid sitting long on damp ground.
• Late Afternoon: Head to a nearby viewpoint for sunset — dry-season skies are often clear with streaks of cloud.
• Evening: Dinner with local specialties (black pork, hill chicken, forest vegetables). Repack for summit day: water, snacks, warm clothes, flashlight, power bank. Sleep early.

Day 2:

• Early Morning: Begin your Phia Oắc National Park summit trek well-prepared: carry 1.5–2 liters of water per person, energy snacks, trekking poles, and a sturdy windbreaker for changing mountain weather.
• Late Morning: Near the peak, time your arrival for the “sea of clouds” 30–60 minutes after sunrise.
• Afternoon: Descend and explore Tĩnh Túc’s French colonial ruins. Have lunch, then return to Cao Bằng or continue to Bản Giốc/Pác Bó if your schedule allows.

Optional 3–4 Day Extension:

• Day 3: Bản Giốc – Trùng Khánh
• Day 4: Pác Bó – Thang Hen Lake → return to Hanoi via QL3.

Eat & stay – Warm meals, deep sleep

Accommodation: You can find cozy homestays and guesthouses in Nguyên Bình – Tĩnh Túc area near Phia Oắc National Park or along the park’s access roads. Prioritize accommodations with hot water, thick blankets, and heaters to stay warm during the chilly winter nights.

Dining: preorder local dishes (hill chicken, native pork, stream fish, sour bamboo shoots, forest greens). Bring ginger tea, hot cocoa, or instant soup for mid-trek breaks.
Local shopping: support locals by buying agricultural or handmade products; check for sustainable sourcing.

Find full Food & Stay details on the ExoTrails app.

Essential packing checklist (Seasonal guide)

Before setting out to explore Phia Oắc National Park, make sure you’re fully equipped for the mountain’s shifting moods. From essential trekking gear and first aid to cold-weather and rainy-season protection, thoughtful preparation ensures a safe and comfortable journey through this wild and enchanting landscape.

Year-round Essentials:

• Trekking shoes with grip; trekking pole
• 20–30L backpack; light raincoat; headlamp; power bank; light gloves; waterproof phone pouch
• 1.5–2L water/person; energy snacks (nuts, granola bars, chocolate)
• First aid kit (bandages, stomach medicine, fever reducer, antiseptic, heat patch)

Winter (Cold–Wind–Moisture Protection Priority):

• Thermal base layer + midlayer (fleece/wool) + insulated or windproof outer layer
• Wool hat, buff/scarf, thick gloves, extra wool socks
• Insulated water bottle, hand warmers

Rainy Season:

• Rain cover for backpack, dry bag, anti-slip shoes, leech repellent if necessary.

Conclusion

High above the clouds, where frost glimmers on moss and time seems to slow, Phia Oắc National Park remains one of Vietnam’s last untouched frontiers. It’s where travelers find not only breathtaking views but also quiet moments of connection — with the forest, the mountains, and themselves. 

Whether you come for the challenge of the summit, the serenity of the moss forest, or the whispers of colonial history in Tĩnh Túc, each step at Phia Oắc National Park is a reminder of nature’s timeless grace and the beauty of venturing where few have gone before.

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