Nahuel Huapí is the oldest Argentinian national park. It has been established 1934, but the nucleus of the park is the land donated to federal government by Perito Moreno in 1903. Park covers approximately 705 square kilometers. The park is located in the southwest corner of Río Negro province  on the borders with Chile. Largest city and a good base camp for exploration is resort city San Carlos de Bariloche. Park is famous for its rich biodiversity – it covers many biotopes due to attitudes ranging from 3000 m to 700m and precipitation ranging from rain forests with 4000 mm/yr on the western slopes to steppes with less than 300 mm/yr on the eastern side. 

There are many lakes in the park - Nahuel Huapi, Lago Mascardi, Lago Gutiérrez, Lago Traful, Lago Moreno, and Lago Guillelmo. Lake Nahuel Huapi contains several islands, including Isla Huemul, which hosted the Huemul Project in 1948