In which country is Aconcagua, the highest mountain in the Andes?

Aconcagua, the highest mountain in the Andes, is in Argentina.

The mountain stands in Mendoza Province near Argentina’s border with Chile, within the Principal Cordillera of the Andes. At about 6,967 meters, it is the highest peak in the Americas and outside Asia, making it one of the Seven Summits—the highest mountains on each continent.

Aconcagua’s great height reflects the geological forces that built the Andes. The Nazca Plate is being forced beneath the South American Plate, compressing and uplifting the continental margin. Although Aconcagua began as a volcanic complex, volcanic activity ended millions of years ago; later tectonic uplift raised its rocks into the enormous mountain seen today.

The peak is sometimes mistaken for a Chilean mountain because it sits close to the international boundary and many views and climbing approaches involve Chilean geography. The summit itself is in Argentina. The normal northwest route is technically relatively straightforward for a mountain of its height, but altitude, cold, storms, and severe weather make an ascent highly demanding.