The Tren a las Nubes (Train to the Clouds) is one of the most extraordinary railway journeys on Earth. The route runs from San Antonio de los Cobres (3,775m), a small Puna town three hours by road from Salta, to the La Polvorilla Viaduct at 4,220 meters above sea level. The viaduct itself is an engineering marvel: a curved steel bridge spanning 224 meters across a desert gorge with no central supports, built between 1921 and 1948 as part of a project to connect Argentina's northwest with Chile by rail. The train carries over 150,000 passengers per year, making it one of the most popular tourist railways in South America. It operates from April through November (dry season). Ticket prices range from $80-120 USD for the full excursion including bus transfers from Salta.
Getting there — distances & times
| From | Distance | Flight | Bus | Drive |
|---|---|---|---|---|
| Buenos Aires (EZE) | 1500 km | 2 h 20 | 20–22 h | 15–17 h |
| New York (JFK) | 9400 km | 12 h + 2 h 20 layover | — | — |
| Madrid (MAD) | 11300 km | 14 h + 2 h 20 layover | — | — |
| São Paulo (GRU) | 2800 km | 4 h 30 | — | — |
| Córdoba | 890 km | 1 h 30 | 11–13 h | 9–10 h |
| Mendoza | 1200 km | 2 h | 17–19 h | 13–15 h |
Month-by-month climate
| Month | Temp. | Rain | Crowds | Note |
|---|---|---|---|---|
| Jan | 16° / 28°C | 180 mm | Rainy summer | |
| Feb | 15° / 27°C | 155 mm | ||
| Mar | 14° / 26°C | 110 mm | ||
| Apr | 11° / 24°C | 30 mm | Dry season starts | |
| May | 8° / 22°C | 8 mm | ||
| Jun | 5° / 20°C | 3 mm | ||
| Jul | 4° / 20°C | 3 mm | Winter break | |
| Aug | 6° / 22°C | 5 mm | ||
| Sep | 9° / 25°C | 10 mm | Clear skies | |
| Oct | 12° / 27°C | 25 mm | ||
| Nov | 14° / 28°C | 60 mm | ||
| Dec | 16° / 28°C | 140 mm | Holidays |
Typical prices by category
| Category | Budget | Mid-range | Luxury |
|---|---|---|---|
| Hotel/night | USD 15–25 | USD 50–90 | USD 150–350 |
| Food/day | USD 12–18 | USD 25–40 | USD 60–120 |
| Day tour | USD 40–55 | USD 60–90 | USD 120–200 |
| Car rental/day | USD 30–45 | USD 50–70 | USD 90–150 |
Approximate ranges in USD as of April 2026. May vary with Argentine peso exchange rate.
The Experience
The full excursion departs Salta at approximately 6:00 AM by bus. The 3-hour drive to San Antonio de los Cobres follows National Route 51 through the Quebrada del Toro gorge, climbing from 1,187m to 3,775m through increasingly dramatic high-altitude Puna desert. At San Antonio, passengers board the train for the journey to the La Polvorilla Viaduct. The landscape is vast, arid and punctuated by mountains exceeding 5,000 meters and scattered llama herds. At the viaduct, the train stops for approximately 30 minutes for photographs and to take in the engineering and the views. The return follows the same route. Lunch in San Antonio de los Cobres (included in most packages), then bus back to Salta, arriving 8-10 PM.
Altitude Warning
The viaduct is at 4,220 meters. Altitude sickness (soroche) is a real concern, especially for visitors arriving directly from sea level. Common symptoms include headache, nausea and shortness of breath. The train has medical staff with oxygen on board. Pack sunscreen (UV exposure at altitude is intense), warm layers (temperatures can drop below freezing even in sunny weather), and coca leaves or altitude tablets (available at pharmacies in Salta). Drink plenty of water the day before. The bus ride provides gradual ascent that helps with acclimatization.
Booking & Practical Tips
- Book early: Tickets sell out weeks in advance during peak months (July school holidays, Easter, September-October).
- Official website: trenalasnubes.com.ar
- Season: April through November only. No service December-March.
- What to bring: Warm layers, sunscreen SPF 50+, sunglasses, hat, water, coca leaves, light snacks.
- Alternative: Even without the train, the drive from Salta to San Antonio de los Cobres through the Quebrada del Toro is one of the most spectacular road journeys in the Argentine Andes (165 km, fully paved).
