The national parks of Argentina are one of the country's principal lures, encompassing the gamut of ecosystems and scenery that exist here, from arid dry chaco thornscrub to subtropical jungle, from high Andean peaks to Atlantic coastline. Though some parks were established purely for their fabulous scenery, many others - especially the more recently established ones - were created to protect examples of different ecosystems. In addition, some protect important archeological or geological sites. The parks vary in size from the minuscule botanical reserve of Colonia Benítez in Chaco Province, less than a tenth of a square kilometre in size, to the grand and savage Parque Nacional Los Glaciares in Santa Cruz, which covers some six thousand square kilometres.

These national protected areas fall into four different categories - Parques Nacionales, Reservas Naturales, Reservas Naturales Estrictas , and Monumentos Naturales - but the distinctions between them have little relevance to the tourist, although it is as well to be aware that a monumento natural is used to refer to individual species, such as the native Patagonian Andean deer, the huemul , as well as to places. More relevant to the tourist are the different degrees of protection that exist within the parks: strict scientific zones ( zonas intangibles ) that are not open to the general public, zones with routes of public access that are otherwise under full protection, and buffer zones where locals engage in certain limited forms of sustainable exploitation (such as forestry and the hunting of introduced species). The situation is complicated by the presence of indigenous communities in some parks, while in others there are enclaves of privately owned land which even guardaparques (rangers) must ask permission to enter.

The most famous parks of all are the subtropical Iguazú in the northeastern province of Misiones, with its famous waterfalls, and the great Patagonian parks that protect the lakes and subantarctic forests of the mountainous border with Chile - most notably Nahuel Huapi , by Bariloche in Río Negro Province, and Los Glaciares , near El Calafate in Santa Cruz, with its twin attractions of the Perito Moreno Glacier and the Fitz Roy trekking sector. Lanín , with its famous volcano and monkey puzzle forests, Los Alerces and Perito Moreno (distinct from the glacier) are two other mighty Patagonian Andean parks, and in Parque Nacional Tierra del Fuego the Andes meet the Beagle Channel. One of the easiest national parks to access from Buenos Aires is El Palmar , in the province of Entre Ríos, a savannah plain studded with graceful native palms. Famous for its cloudforest are the northwestern mountain parks of Baritú, Calilegua and El Rey . Geologically fascinating are the spectacular canyon of Talampaya in La Rioja Province, and the Bosques Petrificados (Petrified Forests) in Santa Cruz.

In addition to the national parks, Argentina has an array of provincial nature reserves and protected areas, the most exceptional of which is the Península Valdés , on the coast of Chubut near Puerto Madryn. Valdés is one of the country's leading tourist attractions and the most reliable of all destinations for seeing wildlife. Its marine mammals are the star attraction, principally the southern right whales which come to breed here. It is also one of the finest places to see the animals of the Patagonian steppe. Another good place for spotting this wildlife is at Punta Tombo , also in Chubut Province. This reserve is most famous for sheltering the largest colony of Magellanic penguins on the continent. The Esteros de Iberá swampland in Corrientes Province, is good for spotting cayman and capybara as well as a remarkable variety of birdlife. In Mendoza, the Parque Provincial Aconcagua was set up to protect South America's highest peak, while Ischigualasto in San Juan protects a famous, desertified lunar landscape with bizarrely eroded geological formations.