A 155-kilometer valley where the mountains look hand-painted. In Purmamarca, the Hill of Seven Colors shifts tone with the light of day; in the adobe villages, pre-Columbian and colonial history breathes from every corner. You climb among giant cardón cacti, hear a distant quena flute and eat a Salta-style empanada under the altiplano sun. The Argentine northwest, a World Heritage Site, in its purest form.