Aconcagua is bounded by the Valle de las Vacas to the north and east and the Valle de los Horcones Inferior to the West and South. The mountain and its surroundings are part of the Aconcagua Provincial Park. The mountain has a number of glaciers. The largest glacier is the Ventisquero Horcones Inferior at about 10 km long which descends from the south face to about 3600m altitude near the Confluencia camp. Two other large glacier systems are the Ventisquero de las Vacas Sur and Glaciar Este/Ventisquero Relinchos system at about 5 km long. However the most well-known is the north-eastern or Polish Glacier, a common route of ascent.
The mountain was created by the subduction of the Nazca Plate beneath the South American plate during the geologically recent Andean orogeny; however, it is not a volcano. The origin of the name is contested; it is either from the Arauca Aconca-Hue, which refers to the Aconcagua River and means 'comes from the other side', the Quechua Ackon Cahuak, meaning 'Sentinel of Stone', or Quechua Anco Cahuac, 'White Sentinel'.