Red deserts, dusty adobe villages, and sparkling white churches are what you'll find in the northwestern part of Argentina. You might indeed think you were in Bolivia or Peru as you savor the indigenous flair of a place steeped in history. Here you'll find the ruins of ancient civilizations -- be it the terraced settlements of the Quilmes Indians or the mysterious standing stones of the Tafi tribe. You can gaze upon the wonderful baroque art and colonial splendor of Salta city. You can follow the narrative of the glorious Gaucho Wars that beat off the Spanish and then gave rise to their own strongmen, such as Martín Güemes and Julio A. Roca. And here begins RN 40, that epic Andean roadway that forms the backbone of Argentina. In the Northwest alone it passes by vineyards, cactus hills, rainforests, tobacco fields, sugar-cane country, dinosaur parks, and vast empty salt plains. All this and more make the Northwest of Argentina the very heart of South America.
Exploring the Region -- The Northwest is best explored by car. Although there is bus service between most towns, a car allows you to explore at ease the rainbow-colored mountain ranges of Humahuaca or the rugged scenery of Calchaquíes Valley. Be prepared for long distances and hidden marvels off the beaten track, such as the Indian settlement of Quilmes, the breathtaking canyons of Talampaya, or the dinosaur remains of Ischigualasto. Most towns, such as Salta and Tilcara, are best explored by foot, and the wineries of Cafayate are easily accessed by bicycle. Three days at a minimum to 5 days should allow you enough time to experience the flavor of the region.
Another way to discover the Northwest is aboard the Tren a las Nubes (Train to the Clouds), a daylong journey that takes you from Salta toward the Chilean border and back. It runs only from April to November.