Hiking and Mountaineering

November through March is the best time for hiking and climbing. You can arrange day hikes with area tour operators. Of the longer treks, the most popular lasts four to seven days and begins at Puente del Inca (2,950 meters/9,680 feet), where you spend a night to get acclimated, and then set out for Aconcagua's base camp. On the first day, a steady climb takes you to Confluencia, where most people spend two nights and enjoy a day hike to the south wall and its incredible glacier. The hike continues to the Plaza de Mulas (4,260 meters/13,976 feet) and ends at the base camp for climbers making a final ascent on Cerro Aconcagua.

Fernando Grajales. Guiding since 1976, Fernando Grajales is a veteran of many Aconcagua ascents. His company leads 18-day excursions to the summit in season. 261/15–658–8855; 800/516–6962; www.grajales.net.

Inka Expeditions. This outfit has 20 years of experience leading tours both to the base camp and to Aconcagua's summit. Other treks in the area can also be organized. 261/425–0871; www.inka.com.ar.