For wine lovers, Mendoza  alone merits at least a week; even those with only a passing interest in the vine should spend a few days, ideally during the March Vendimia (harvest festival, when reservations are almost obligatory).
The upper Río Mendoza valley , en route to Chile, is close enough for recreational activities like white-water rafting and even winter skiing, though there are also accommodations at the slopes of Los Penitentes . Wine aficionados can extend their stay to Uco vineyards  and San Rafael wineries , to the south.
Whether hiking or climbing, Aconcagua  is a trip in its own right. A three-day hike is possible, but the trek to and from base camp is a 10-day commitment, and climbers should budget three weeks for a summit assault—whether successful or not.
Visiting the desert parks of San Juan  and San Luis , plus La Rioja’s Talampaya , would ideally require a week because of the distances between them, even given only a day at each unit (plus a recommended detour to the Difunta Correa shrine ). It’s best to avoid these areas in summer’s heat, when rare storms can cause flash floods.
Córdoba ’s urban attractions are independent of the seasons, and its Sierras  are popular throughout the year (but crowded in summer). Many visitors cross back and forth between Córdoba and the Sierras of San Luis.