Sendero de los Seismiles — Paso San Francisco to Ojos del Salado Base Camp via the Puna de Atacama Volcano Corridor

The road from Paso San Francisco on the Chilean-Argentine border toward the Ojos del Salado base camp is not a route you stumble onto — you plan it, prepare for it, and still get humbled by it. The crossing climbs through the Puna de Atacama at sustained elevations above 4,500 meters, threading between cinder cone volcanoes, salt flats, and wind-scoured lava fields. The Argentine side out of Fiambalá is the classic approach: a long gravel descent through quebrada country gives way to altitude desert that doesn’t let up. By the time you reach Refugio Tejos at roughly 5,760m, the air is thin enough to make changing a tyre feel like a near-death experience. This is real expedition driving — Ojos del Salado, at 6,893m, looms the whole time like it owns you.

You need a well-prepared, high-clearance 4WD with a cold-climate engine tune and tyres that can handle frozen gravel and loose volcanic rock — a diesel Land Cruiser 70 or similar is the benchmark. AMS (acute mountain sickness) is a genuine threat above 4,000m; acclimatize in San Pedro de Atacama or Fiambalá first. Permits are required on the Chilean side through DIFROL. Fuel up completely in Fiambalá or Copiapó — there is nothing out there. Best window is December through March. This route rewards the prepared with absolute silence, jaw-dropping volcanic scenery, and the honest satisfaction of driving somewhere very few vehicles have been.