The UNESCO-listed Quebrada de Humahuaca is an unmissable sight. Once you have left the suburbs of Jujuy, the road climbs in a series of impressive hairpins. On either side of the narrow valley, mountains and hills appear in a streaked palette of red, green and yellow, along with the occasional splash of blue. The villages here seem to rise up out of the earth along Ruta 9. The nearby Andes are preceded by high desert plateaux home to shepherds and their flocks of sheep and llamas.