The border between Argentina and Bolivia marks a significant cultural and geographical shift, taking you from the lower-lying Valles Calchaquíes of northern Argentina into the high-altitude Altiplano. The atmosphere here is distinctly Andean, with a strong indigenous Quechua and Aymara heritage visible on both sides of the frontier. There are three main crossing points for travelers. The most popular is the Horacio Guzmán International Bridge, which connects La Quiaca in Argentina with Villazón in Bolivia. This route sits at a dizzying 3,400 meters (over 11,000 feet) above sea level, and the change in altitude is immediate and palpable.
Another important crossing connects Salvador Mazza (Argentina) with Yacuiba (Bolivia) in the warmer, lower-altitude Gran Chaco region. A third, smaller crossing exists at Aguas Blancas, connecting to Bermejo in Bolivia. When you cross, especially at La Quiaca, the change is striking. The air thins, the light intensifies, and the culture shifts. It is highly recommended to give yourself at least a day to acclimatize to the altitude before undertaking any strenuous activity. This region is also where you will first encounter the widespread cultural importance of the coca leaf in Bolivia, which is legally chewed by locals to mitigate the effects of high altitude.