After several days of winery visits and decadent lunches, I was ready to work off some calories in the mountains all around the province. If, like me, you need a reward for your adventuring, Trekking Travel leads afternoon horseback rides into the rocky foothills near Cacheuta Hot Springs, where you can soak in mineral waters before heading back to town (011-54/261-421-0450, trekking-travel.com.ar, two-hour tours from $80). Or sign on with outfitter Argentina Rafting Expeditions for a day of hiking or white-water rafting down the Pueblo del Rio (011-54/262-448-2037, argentinarafting.com, half-day trips from $25). At the end of my stay, I rented a car and drove about three and a half hours to take in Aconcagua, South America's tallest mountain. Near the entrance to Aconcagua Park, you can hike around a glacier lake and swim in the hot springs at Puente del Inca. Longer treks require permits, and you'll understand why when you come to the Cemetery of the Andinistas—the final rest stop for the many climbers who've died trying to scale the 22,841-foot peak (aconcagua.com, entrance fee $20).