2 Best Sights in The Northwest, Argentina

If you can endure a harrowing five-hour, 50-km (31-mile) ride east from Humahuaca on an unpaved cliffside road, you'll be rewarded with one of Argentina's most stunning settings. (Take the bus from Humahuaca rather than driving yourself; you really have to know the road, as the bus drivers do, to negotiate it safely.) This cobblestoned town, which clings to sheer rock, has become an increasingly popular stop despite its small size. It has just a couple of accommodations, the Hotel Iruya ( 3887/442–3536) and Hostal Milmahuasi ( 3887/619–1591), but many villagers offer rooms for rent. The busiest times to visit are at Easter and during the first and second weekends in October, when the village celebrates its festival. There are some good hikes from Iruya to even more remote towns like San Isidro, three hours away through the mountains. For more information and guide recommendations, call Adelina López at the Tourist Office ( 3887/155–094–799) or visit  www.iruyaonline.com.

The first 50 km (30 miles) of the direct road to Salta (or the last stretch if you don't come via Cachi and Molinos) is known as the Gorge of the Shells, and breathtaking scenery makes it an attraction in its own right. Various rock formations have been eroded into wildly different shapes that have been nicknamed the Windows, the Castles, the Frog, the Friar—each name seems fanciful, that is until the road winds around the corner and you're actually confronted by the formation itself. The climax is the Amphitheater, sometimes used as a venue for proper orchestras thanks to its outstanding natural acoustics; wandering minstrels offer impromptu performances.  If you've rented a car, keep valuables out of view as thieves have become more prevalent at the Amphitheater.