North of RN 7, nearly hugging the Chilean border, Parque Provincial Aconcagua protects 710 sq km of the wild high country surrounding the western hemisphere’s highest summit, 6962m (922,841ft) Cerro Aconcagua. Passing motorists (and those who time their buses correctly) can stop to enjoy the view of the peak from Laguna Los Horcones, a 2km walk from the parking lot just north of the highway.

Only highly experienced climbers should consider climbing Aconcagua without the relative safety of an organized tour – even then, it's a serious climb that requires training and preparation.