Nahuel Huapi National Park is the oldest national park in Argentina, established in 1934. It surrounds Nahuel Huapi Lake in the foothills of the Patagonian Andes. The largest of the national parks in the region, it has an area of 7,050 km², or nearly 2 million acres. Its landscapes represent the north Patagonian Andean Zone consisting of three types, namely, the Altoandino, the Andino-Patagónico and the Patagonian steppe. It also represents small parts of the Valdivian Rainforest.
The park and the reserve lie at an altitude of 720–3,574 metres, and are designated under IUCN management categories II and IV. The park is completely protected while the reserve is partially protected. The national park is dominated by the high mountain chain of the Andes, many lakes, rapid rivers, waterfalls, snow-clad peaks, glaciers and extensive forests. It is bordered by Chile on its western side.