Peru occupies 1,285,216 square kilometers on the western edge of South America. The country divides into three distinct geographical zones running north to south: a narrow coastal desert strip along the Pacific Ocean, the Andes Mountains rising through the interior, and the Amazon rainforest covering the eastern lowlands. This arrangement produces extreme topographical variation within relatively short distances. A traveler can move from sea level at the Pacific coast to 6,768 meters at Huascarán's summit to dense tropical forest at 200 meters elevation within 300 kilometers of linear distance.
The Andes Mountains dominate Peru's geography. The range enters from Ecuador in the north and extends through the entire length of the country to Chile and Bolivia in the south. Within Peru, the Andes split into three parallel cordilleras in several regions, creating high-altitude valleys and plateaus between the ranges. The Cordillera Blanca in Ancash Department contains Peru's highest concentration of glaciated peaks. Huascarán, the tallest mountain in Peru and the fourth highest in the Western Hemisphere, reaches 6,768 meters. The Cordillera Blanca holds more than 50 peaks exceeding 5,700 meters and contains approximately 722 individual glaciers covering 723 square kilometers, according to the Autoridad Nacional del Agua's 2018 inventory. These glaciers have retreated 34 percent in surface area since 1970 based on measurements comparing aerial photography from that period with recent satellite imagery.
The Cordillera Huayhuash sits south of the Cordillera Blanca. This compact range spans approximately 30 kilometers north to south but contains six peaks above 6,000 meters, including Yerupajá at 6,634 meters, the second highest mountain in Peru. The circuit trek around the Cordillera Huayhuash covers roughly 120 kilometers and typically requires eight to twelve days depending on route variations and acclimatization schedules. The route crosses multiple passes exceeding 4,750 meters.
Lake Titicaca occupies the Altiplano on Peru's southeastern border with Bolivia at 3,812 meters elevation. The lake covers 8,372 square kilometers with Peru holding roughly 56 percent of the surface area and Bolivia 44 percent. Maximum depth reaches 281 meters in the lake's northeastern section near Isla Soto. More than 25 rivers flow into Lake Titicaca, with the Ramis River contributing the largest volume. The lake has one outlet, the Desaguadero River, which flows south into Bolivia. Lake Titicaca constitutes the largest freshwater lake by volume in South America and qualifies as the highest navigable lake of significant size globally, though exact ranking depends on definitional criteria for "navigable" and "significant."
Peru's Pacific coastline extends 2,414 kilometers from the Ecuadorian border at Tumbes to the Chilean border at Tacna. The coast consists primarily of desert interrupted by narrow river valleys where water descending from the Andes permits agriculture and concentrates settlement. The Humboldt Current flows northward along the coast, bringing cold Antarctic water that creates temperature inversions preventing rainfall despite high humidity. Coastal cities frequently experience garúa, a persistent fog that blankets the region from May through October without producing measurable precipitation. Lima, positioned on the central coast, receives an average of only 13 millimeters of rain annually despite year-round humidity typically exceeding 80 percent.
The Sechura Desert in northwestern Peru ranks as the largest continuous desert area along the Peruvian coast, extending across portions of Piura and Lambayeque departments. The desert reaches approximately 188 kilometers in length and 100 kilometers at maximum width. Surface elevations range from sea level to 300 meters. During El Niño events, the Sechura can receive substantial rainfall that temporarily transforms portions of the desert. The 1997-98 El Niño event brought more than 200 millimeters of precipitation to normally arid areas, producing temporary lakes and triggering explosive growth of dormant vegetation.
The Nazca Desert occupies coastal plains south of Lima. This hyperarid environment preserves the Nazca Lines, geoglyphs created by removing reddish pebbles to reveal lighter ground beneath. The lines span approximately 450 square kilometers between the towns of Nazca and Palpa. More than 800 straight lines, 300 geometric figures, and 70 animal and plant designs have been documented. The largest figures exceed 200 meters in length. The lines date primarily to 500 BCE through 500 CE based on ceramic fragments found at sites where stakes anchored measuring ropes. The figures remain visible because the region receives less than 4 millimeters of annual rainfall and experiences minimal wind erosion due to ground heat creating a protective air layer.
The Paracas Peninsula projects into the Pacific Ocean approximately 250 kilometers south of Lima. Paracas National Reserve protects 335,000 hectares encompassing desert coastline, beaches, cliffs, and ocean. The reserve supports colonies of Humboldt penguins, Peruvian boobies, and Peruvian pelicans on offshore islands. The Ballestas Islands, located within the reserve boundaries, host estimated populations exceeding 4,000 Humboldt penguins and several thousand South American sea lions according to SERNANP monitoring data from 2019. The coastline features wind-carved rock formations and red sand beaches colored by eroded granite. The "Candelabra" geoglyph, a 181-meter tall figure carved into the northern slope of the peninsula, remains visible from 20 kilometers at sea. Dating and cultural attribution remain uncertain, with radiocarbon analysis of organic materials near the figure producing dates ranging from 200 BCE to 200 CE.
Colca Canyon cuts through the Andes in southern Peru near Arequipa. Measured from the rim at Huambo to the Colca River below, the canyon reaches 3,270 meters in depth, more than twice the depth of the Grand Canyon measured rim to river. The canyon formed as the Colca River eroded downward while tectonic uplift raised the surrounding plateau. The Mismi massif southeast of the canyon contains springs that feed tributaries considered the most distant source of the Amazon River system. A 1996 National Geographic expedition documented the spring at Nevado Mismi at 5,597 meters as the point marking the greatest distance from the Amazon's mouth. This determination remains accepted though alternative source claims exist.
Cotahuasi Canyon parallels Colca Canyon approximately 200 kilometers to the northwest. Maximum depth at Cotahuasi reaches 3,535 meters from rim to river, measured at the section near Quechualla. Both canyons support pre-Columbian agricultural terraces still under cultivation. Andean condors inhabit both canyon systems. These birds rank among the world's largest flying birds, with wingspans reaching 3.2 meters and weights up to 15 kilograms for males. Condors utilize thermal updrafts from the canyon depths to gain altitude without sustained flapping flight. Organized viewing areas near Cruz del Condor in Colca Canyon and similar locations in Cotahuasi offer reliable morning sightings, particularly from May through December when thermals develop consistently.
The Amazon rainforest covers approximately 782,000 square kilometers in Peru, representing 60 percent of the country's land area. Peru holds 13 percent of the total Amazon basin and ranks second after Brazil in Amazonian territory. The Peruvian Amazon extends from the eastern Andean slopes at approximately 800 meters down to 80 meters elevation at the Brazilian border. Three major river systems drain this region: the Marañón, Ucayali, and Madre de Dios rivers, all ultimately joining to form the Amazon proper.
The Marañón River originates in the Andes of northern Peru and flows 1,737 kilometers northward then eastward through deep canyons before joining the Ucayali near Nauta to form the Amazon River proper. The Marañón cuts through canyons exceeding 1,500 meters in depth in its upper reaches. The river remains navigable by motorized vessels from Iquitos upstream to Pongo de Manseriche, a 5-kilometer gorge where the river compresses to 45 meters width and flows through rapids unsuitable for standard commercial traffic.