Ruta Nacional 40 Paso de Agua Negra International Route

The Paso de Agua Negra sits at 4,765 meters above sea level, making it one of the highest drivable passes in South America. This remote border crossing follows pre-Columbian trade routes through the high Andes, passing abandoned mining camps and salt-crusted lagoons where flamingos feed in the shadow of 6,000-meter peaks. The route branches off RN40 near Iglesia, climbing through the Cordillera de los Andes via switchbacks carved from solid rock, with the final approach crossing the Salinas Grandes salt flat.

This is expert-level high-altitude driving requiring serious preparation and mechanically sound 4WD vehicles. Altitude sickness hits hard above 4,000 meters, and weather changes without warning year-round. Best attempted November through March when snow clears, but even summer crossings demand tire chains, extra fuel, and emergency gear. Border formalities on the Chilean side can take hours, and there’s no fuel for 200+ kilometers. What you get is bragging rights to one of the world’s most spectacular and punishing mountain crossings.