The Andes Mountains form Argentina's entire western border with Chile, extending approximately 5,500 kilometers from the border with Bolivia in the north to Tierra del Fuego in the south. This represents roughly one-quarter of the Andes' total length of 7,000 kilometers. The Argentine section of the range varies dramatically in character by latitude, creating distinct subregions with different geological compositions, elevations, and climate zones.
Aconcagua stands at 6,961 meters above sea level in Mendoza Province, making it the highest peak in the Western and Southern Hemispheres. The mountain sits within Aconcagua Provincial Park, approximately 112 kilometers northwest of Mendoza city. Polish climber Matthias Zurbriggen completed the first confirmed ascent on January 14, 1897, via the northern route now called the Normal Route. The mountain attracts approximately 3,500 summit attempts annually, with success rates fluctuating between 30 and 40 percent depending on season and weather conditions. The standard climbing season runs from mid-November through mid-March, when temperatures at the summit can still drop to minus 40 degrees Celsius. The Normal Route requires no technical climbing skills but demands acclimatization to extreme altitude, with most expeditions requiring 18 to 21 days from Mendoza city to summit and return.
The Puna de Atacama occupies northwestern Argentina in Catamarca, Salta, and Jujuy provinces, forming the southern extension of the Altiplano plateau. This high-altitude desert sits between 3,400 and 4,800 meters elevation, characterized by salt flats, volcanic formations, and minimal precipitation averaging below 200 millimeters annually. Temperatures swing from daytime highs of 25 degrees Celsius to nighttime lows of minus 20 degrees Celsius. The region contains numerous stratovolcanoes including Ojos del Salado at 6,893 meters, the world's highest active volcano located on the Argentina-Chile border. The Puna receives less than 50 millimeters of rain in most years, creating one of Earth's driest environments outside Antarctica.
Salinas Grandes spreads across 212 square kilometers in Jujuy and Salta provinces at 3,450 meters elevation. The salt flat reaches up to 30 centimeters thick in its central sections, formed by evaporation of ancient lake beds over thousands of years. The mineral composition measures approximately 95 percent sodium chloride. Small-scale mining operations extract roughly 10,000 tons of salt annually using traditional hand-cutting methods. The surrounding landscape transitions abruptly to the Sierra de Córdoba mountains, creating visual contrast visible from Highway 52 connecting Purmamarca to the Chilean border.
Patagonia encompasses all Argentine territory south of the Colorado River at approximately 37 degrees south latitude, covering 673,000 square kilometers or roughly 28 percent of Argentina's land area. The region extends 2,300 kilometers from north to south and reaches maximum widths of 800 kilometers. Geologically, Patagonia consists primarily of extra-Andean tablelands characterized by mesetas, flat-topped formations with steep sides carved by glacial and fluvial erosion. These plateaus range from 800 to 1,500 meters elevation in most areas. The Patagonian climate operates under a rain shadow effect created by the Andes, which blocks Pacific moisture, resulting in annual precipitation below 150 millimeters across vast interior sections.
The Pampas occupies approximately 760,000 square kilometers of central Argentina, extending roughly from 33 degrees to 39 degrees south latitude. This virtually flat plain experiences elevation changes of less than 300 meters across distances exceeding 500 kilometers. The region divides into humid pampas east of approximately 62 degrees west longitude, receiving 600 to 1,000 millimeters annual rainfall, and dry pampas to the west, receiving 300 to 600 millimeters. Soil depth reaches 2 to 5 meters in many areas, consisting of wind-deposited loess and decomposed volcanic ash. The absence of natural drainage has created numerous shallow lakes and wetlands. The Pampas produces approximately 85 percent of Argentina's agricultural output measured by value, with wheat, corn, soybeans, and cattle operations dominating land use.
Tierra del Fuego comprises an archipelago separated from mainland South America by the Strait of Magellan, which averages 3 kilometers wide at its narrowest point. The main island covers 48,100 square kilometers, with Argentina controlling the eastern 21,571 square kilometers and Chile the western portion. The Andes reach their southern terminus here, with peaks rarely exceeding 1,500 meters. Mount Cornú rises to 1,490 meters as the highest point in Argentine Tierra del Fuego. Ferdinand Magellan became the first European to navigate these waters in October 1520, naming the region after observing numerous fires lit by indigenous Yaghan and Selk'nam peoples along the shores.
The Beagle Channel separates Tierra del Fuego's main island from numerous smaller islands to the south, running approximately 240 kilometers from west to east. The channel width varies from 5 to 15 kilometers, with depths reaching 400 meters in certain sections. British naval vessel HMS Beagle surveyed these waters during 1826-1830 and again in 1832-1833, with Charles Darwin aboard during the second voyage. The channel's eastern mouth opens into the Atlantic Ocean near the convergence with the Strait of Le Maire. Water temperatures remain between 5 and 9 degrees Celsius year-round. The Argentine city of Ushuaia sits on the channel's northern shore at 54 degrees 48 minutes south latitude.
Península Valdés extends into the Atlantic Ocean in Chubut Province, connected to the mainland by the Carlos Ameghino Isthmus, which narrows to approximately 5 kilometers wide. The peninsula covers 3,625 square kilometers. Its lowest point, Salina Grande, lies 42 meters below sea level, making it the lowest land point in South America. UNESCO designated Península Valdés a World Heritage Site in 1999 for its marine mammal populations. Southern right whales arrive annually between June and December for breeding and calving, with population counts exceeding 2,300 individuals documented in 2019. Southern elephant seals establish breeding colonies on the peninsula's beaches, with males reaching weights of 3,700 kilograms. Orcas practice intentional beaching behavior here between February and April, launching themselves onto beaches to capture sea lion pups.
The Gran Chaco covers approximately 647,000 square kilometers across Argentina, Paraguay, Bolivia, and Brazil. The Argentine section occupies roughly 250,000 square kilometers across Formosa, Chaco, Santiago del Estero, and northern Santa Fe provinces. This lowland plain slopes gently from 500 meters elevation at the Andean foothills to near sea level approaching the Paraná River, creating a gradient of approximately 0.04 percent. The region experiences semi-arid to sub-humid conditions with annual rainfall between 500 and 1,000 millimeters concentrated in November through March. Summer temperatures frequently exceed 45 degrees Celsius. The Chaco ecosystem contains approximately 3,400 plant species, with quebracho trees historically dominating forest composition before extensive logging during the early 20th century reduced forest coverage by an estimated 60 percent.
The Paraná River extends 3,032 kilometers from its headwaters at the confluence of the Paranaíba and Grande rivers in Brazil to its delta at the Río de la Plata. Approximately 1,200 kilometers flow through or along Argentine territory. The river's discharge averages 17,300 cubic meters per second measured at Corrientes, making it the world's eighth-largest river by discharge volume. The Paraná Delta begins near Diamante, Entre Ríos, approximately 320 kilometers upstream from Buenos Aires, spreading across 17,500 square kilometers of wetlands, islands, and channels. Sediment deposition extends the delta into the Río de la Plata at rates measuring 50 to 90 meters annually in some locations. The Yacyretá Dam, completed in 1994 near the Argentina-Paraguay border, creates a reservoir covering 1,600 square kilometers and generates 20.7 billion kilowatt-hours annually through its 20 turbines.
The Iguazú River flows 1,320 kilometers from its source in Serra do Mar mountains in Brazil to its confluence with the Paraná River at the tri-border junction of Argentina, Brazil, and Paraguay. The river's width varies from 500 to 1,500 meters before reaching the falls. Iguazú Falls consists of approximately 275 individual cataracts spread across 2.7 kilometers, though the precise count fluctuates with water levels. The largest cataract, Garganta del Diablo (Devil's Throat), measures 82 meters high, 150 meters wide, and 700 meters long in a U-shape. Water discharge averages 1,746 cubic meters per second annually, but has reached recorded maximums exceeding 12,800 cubic meters per second during flood events. Spanish conquistador Álvar Núñez Cabeza de Vaca became the first European to document the falls in 1541. Eleanor Roosevelt reportedly remarked "Poor Niagara" upon viewing Iguazú, though no contemporary written record confirms this quotation. The falls' height of 82 meters nearly doubles Niagara's 51-meter drop, and Iguazú's combined width significantly exceeds Niagara's 1,200 meters.
Río de la Plata forms an estuary where the Paraná and Uruguay rivers meet the Atlantic Ocean. Geographers debate its classification as a river, estuary, gulf, or marginal sea. The waterway measures 290 kilometers long from the delta to a line connecting Punta del Este, Uruguay, and Punta Rasa, Argentina. Width increases from approximately 40 kilometers near Buenos Aires to 220 kilometers at its mouth. Despite common translation as "River of Silver," explorer Juan Díaz de Solís first entered these waters in 1516 seeking a passage to the Pacific. The name likely derives from indigenous reports of silver in the region, though substantial silver deposits were never found near the river itself. The estuary's maximum depth reaches only 20 meters in most navigable channels, requiring continuous dredging to maintain shipping lanes to Buenos Aires and Montevideo ports. Sediment discharge from the Paraná and Uruguay rivers totals approximately 160 million tons annually, creating brown coloration visible 100 kilometers offshore during peak discharge periods.
Los Glaciares National Park covers 726,927 hectares in Santa Cruz Province along the Chilean border. The park contains 47 glaciers descending from the Southern Patagonian Ice Field, the world's third-largest freshwater reserve after Antarctica and Greenland. The ice field covers 16,800 square kilometers, with approximately 30 percent located in Argentine territory. Perito Moreno Glacier, the park's most visited formation, covers 250 square kilometers with a terminus face measuring 5 kilometers wide and 74 meters high above Lago Argentino's water surface. The glacier advances at rates measuring 2 meters daily at its center, balanced by calving that maintains a relatively stable terminus position. This stability contrasts with most Patagonian glaciers, which have retreated measurably since the mid-20th century. The glacier periodically dams the Brazo Rico arm of Lago Argentino, creating water level differentials up to 30 meters before ice-bridge collapse. The most recent major rupture occurred in March 2018. UNESCO designated Los Glaciares a World Heritage Site in 1981.
The Southern Patagonian Ice Field extends approximately 350 kilometers from north to south and reaches maximum widths of 60 kilometers. Ice depth exceeds 1,500 meters in certain locations. Glaciologist Federico Reichert conducted the first comprehensive surveys between 1913 and 1914. The ice field feeds 49 major outlet glaciers on the Chilean side and 13 on the Argentine side. Scientific monitoring since 1990 indicates the ice field has lost an average of 23 cubic kilometers of ice annually, representing approximately 0.1 percent annual volume loss. Rising equilibrium line altitudes and decreased precipitation in accumulation zones drive this reduction. Upsala Glacier, the park's largest at approximately 870 square kilometers, has retreated 4.3 kilometers since 2001, with terminus retreat accelerating after 2008.
Nahuel Huapi National Park encompasses 709,162 hectares in Neuquén and Río Negro provinces. Law 12,103 established the park on April 9, 1934, making it Argentina's first national park, though explorer and naturalist Francisco Moreno had donated 7,500 hectares of land for conservation purposes in 1903. Nahuel Huapi Lake covers 557 square kilometers with a maximum depth of 438 meters, making it Argentina's largest and deepest lake. Seven primary arms branch from the main body. The lake's name derives from Mapuche language, with "nahuel" meaning jaguar and "huapi" meaning island, referencing Isla Victoria in the lake's center. The park contains seventeen additional lakes. Cerro Tronador rises to 3,470 meters as the park's highest peak, hosting eight hanging glaciers on its slopes. The mountain straddles the Argentina-Chile border, with its summit marking the boundary. Glacial melt feeds Río Manso, which flows west to the Pacific, and several streams flowing east to the Atlantic, making Tronador a continental water divide.
Iberá Wetlands covers between 12,000 and 15,000 square kilometers in Corrientes Province, representing one of the largest freshwater wetland systems in South America. The name "Iberá" derives from Guaraní language meaning "shining waters." The system consists of interconnected marshes, lakes, lagoons, and floating islands composed of vegetation and peat called embalsados. These floating masses can exceed 2 meters thick and support vegetation including trees. Water depth averages 2 to 4 meters, with maximum depths rarely exceeding 6 meters. The wetlands contain minimal elevation gradient, dropping only 15 meters across 100 kilometers, creating extremely slow water movement that averages 20 to 30 meters daily. This near-stagnant condition promotes high organic content and tannin-stained water. Provincial law established Iberá Provincial Reserve in 1983, protecting 553,000 hectares. In 2018, Corrientes Province expanded protection by creating Iberá National Park covering 158,000 hectares through land donations from Conservation Land Trust and subsequent transfer to national administration.
Quebrada de Humahuaca extends approximately 155 kilometers along the Río Grande valley in Jujuy Province, from Volcán to the Bolivian border near Tres Cruces at elevations between 1,200 and 4,000 meters. The quebrada, or narrow valley, cuts through dramatically stratified geological formations displaying 600 million years of sedimentary history visible in distinct horizontal color bands. Highway 9, the primary route connecting Argentina with Bolivia through La Quiaca border crossing, follows the valley floor. The formation served as a major trade route for 10,000 years, with pre-Columbian cultures including Omaguaca, Atacama, and later Inca using the corridor to transport goods between the Altiplano and lower valleys. Spanish conquistador Diego de Almagro traveled this route in 1535 during his expedition from Peru. UNESCO inscribed Quebrada de Humahuaca on the World Heritage List in 2003 as a cultural landscape. The town of Purmamarca, population approximately 2,200, sits at 2,324 meters elevation near the quebrada's southern entrance. Behind the town, Cerro de los Siete Colores (Hill of Seven Colors) displays mineral strata including pink limestone, white limestone, red clay, and purple mudstone deposited during different geological periods.
Talampaya National Park protects 213,800 hectares in La Rioja Province. Vertical canyon walls reach heights of 143 meters, carved from red sandstone deposited during the Triassic period approximately 250 to 200 million years ago. The Talampaya River, typically dry except during summer flash floods, formed the canyon through episodic erosion over millions of years. The park contains fossils from early dinosaurs and mammal-like reptiles that lived before dinosaurs dominated. Paleontologist Osvaldo Reig discovered Lagosuchus talampayensis fossils here in 1971, representing one of the earliest dinosauromorph species from approximately 236 million years ago. UNESCO designated Talampaya and adjacent Ischigualasto Provincial Park in San Juan Province as a combined World Heritage Site in 2000. The two parks together protect a complete sequence of Triassic period terrestrial fossils spanning 45 million years. Temperatures in Talampaya fluctuate from summer maximums exceeding 45 degrees Celsius to winter minimums below minus 5 degrees Celsius. Annual precipitation averages 120 millimeters.