This is the most complete single-day route through the Atacama's southern altiplano. It combines three sites that each deserve their own visit: Piedras Rojas, with its vivid red rock and turquoise water; the altiplanic lagoons of Miscanti and Miñiques, at the foot of volcanic peaks; and the Atacama salt flat itself, one of the largest in Chile. The route follows a loop south from San Pedro, climbing through desert into the high plateau and returning past the salt flat's edge, where flamingos feed in shallow, mineral-rich water. The light shifts through the day: sharp in the morning, warm at midday, golden in the late afternoon. It is a long day, and worth every hour.