The San Guillermo Biosphere Reserve in the northwest of San Juan Province, Argentina, represents the mixed mountain and highland systems in the foothills and mountains of the Andes. The San Guillermo National Park occupies the core zone.
The Semiarid Pampas ecoregion is located in the center of Argentina. The predominant vegetation consists of grasslands with some shrubs. There are few endemic plants in the ecoregion but the area has a high biodiversity.
The Sierras Pampeanas (also called Central Sierras) is a geographical region and chain of mountains that rise sharply from the surrounding Pampas region of northwestern Argentina. They run parallel to the Andes, cross into seven Argentine provinces, and may be cataloged into sub-regions.
The Southern Patagonian Ice Field, located in the Southern Patagonic Andes between Chile and Argentina, is the world's second largest contiguous extrapolar ice field. It is the bigger of two remnant parts of the Patagonian Ice Sheet, which covered all of southern Chile during the last glacial period,.
The Strait of Magellan is a sea route in southern Chile separating mainland South America to the north and Tierra del Fuego Archipelago to the south. The archipelago is divided by Chile and Argentina and is further separated by the east-west Beagle Channel, just south of Isla Grande de Tierra del Fuego.
The "selva parananese" or Upper Paraná Atlantic Forest is an ecoregion of the tropical moist forests biome and the South American Atlantic Forest biome. The ecoregion stretches across the borders of southern Brazil, eastern Paraguay and northeastern Argentina.
The Uruguayan savanna is a subtropical grassland and savanna ecoregion that extends from the extreme southern part of the Rio Grande do Sul, a Brazilian state, to include the entire country of Uruguay and a small section of the Argentinean province of Entre Ríos.
The Valdivian temperate forests ecoregion is located in the southern cone of South America. It covers a narrow continental strip between the western slope of the Andes and the Pacific Ocean. The forests are characterized by their dense understories of bamboos, ferns, and evergreen trees.
The Yabotí Biosphere Reserve is located in Argentina's Misiones province. The reserve is part of the Misiones Rainforest Corridor within the Brazilian rain forest region which is home to some of the most traditional villages of the Guaraní peoples of Paraguay, Argentina and southern Brazil.