The region's most famous park is Parque Provincial Aconcagua.

Home of 6962m (22,841ft) Cerro Aconcagua, the highest peak outside the Himalayas and a favorite climbing destination. Reaching the summit requires a commitment of at least 13 to 15 days, including acclimatization time. Non-climbers can hike to base camps and refugios (rustic shelters) beneath the permanent snow line; easily, the best and most accessible long hike is to Confluencia from the park entrance at Laguna Horcones.

From December to March, permits are obligatory for both trekking and climbing in Parque Provincial Aconcagua. Park rangers at Laguna Horcones, located only a kilometer past Horcones, the immigration and customs station for travelers entering Argentina from Chile, will not permit visitors to proceed up the Quebrada de los Horcones without one. Fees vary according to the complex park-use seasons.

Source: https://www.lonelyplanet.com/argentina/mendoza-the-central-andes/attractions/parque-provincial-aconcagua/a/poi-sig/460141/1319377