Geoglyphs etched into the Pampa Colorada, a flat arid plateau in southern Peru approximately 400 kilometers south of Lima, were created by the Nazca culture between 500 BCE and 500 CE across a total surveyed area of approximately 450 square kilometers. The plateau sits in the Nazca Desert, one of the driest places on earth, receiving less than 25 millimeters of rainfall annually. The complete corpus of known geoglyphs at the site comprises more than 800 straight lines, over 300 geometric shapes, and a continuously expanding inventory of figurative designs depicting animals, plants, humans, and symbolic scenes. The combined length of all documented lines exceeds 1,300 kilometers. Individual straight lines extend as far as 48 kilometers without deviation. The largest figurative designs span approximately 370 meters from end to end. The hummingbird measures 93 meters in length. The condor measures 134 meters. The monkey measures 93 by 58 meters. The spider measures 47 meters. These are not drawings visible from the ground. The figures covering the desert floor are intelligible as coherent compositions only from aerial altitude or from elevated terrain on surrounding hillsides. The purpose behind their construction has not been definitively established by any published research to date. In September 2024, a joint study by Yamagata University and IBM Research published in the Proceedings of the National Academy of Sciences reported the discovery of 303 new figurative geoglyphs identified through AI analysis of aerial imagery during a six-month field survey, nearly doubling the previously known total of 430 figurative geoglyphs accumulated over nearly 100 years of conventional survey. A further 248 new geoglyphs were announced at Expo 2025 Osaka-Kansai in August 2025, including 160 figurative and 88 geometric designs. At least 968 additional AI-identified candidate sites remain unverified by ground survey as of the date of this article.
Material and Craftsmanship
The Nazca Lines are not drawn, painted, or incised in the conventional sense. They are negative-space geoglyphs produced by removing material from the desert surface rather than adding it. The Pampa Colorada's surface layer consists of reddish-brown iron oxide-coated pebbles and stones lying atop a pale yellow-grey subsoil of a substantially lighter color. Removing the dark surface layer exposes the contrasting pale subsoil beneath, producing lines, shapes, and figures that read as light marks against a dark field from above. The removed pebbles were not discarded. They were piled along the edges of each cleared area in low border mounds, the remnants of which remain visible and confirm the construction sequence. The depth of the cleared trenches is typically 10 to 15 centimeters, rarely exceeding 15 centimeters.
The tools required for this work were simple. Wooden stakes, rope, wooden and bone shovels, and stone picks constitute the full documented toolkit. Wooden stakes were driven into the desert floor at intervals along planned lines, with rope tied between them to guide the clearing crew. Carbon dating of wooden stakes recovered at the ends of several lines provided the primary basis for establishing the construction date range. The figure known as the hummingbird was reproduced in verified condition at full scale by American investigator Joe Nickell in the early 21st century using only wooden stakes, string, and manual labor, confirming that no technology beyond what was available to the Nazca people was required. Nickell's replication directly refuted the 1969 claim by Swiss writer Erich von Däniken that the lines had been constructed by extraterrestrial visitors, a claim that had no basis in the archaeological record.
Two separate production methods are documented across the known figures. The majority of figurative designs were made by clearing only the border of each figure, leaving the interior surface undisturbed and creating an outline design. A smaller number were produced by clearing the interior of the entire figure, producing a solid cleared area of the depicted form. The two methods produce visually distinct results from the air. Both were used simultaneously and at different periods without a documented progression from one method to the other.
The extraordinary preservation of lines created over 2,000 years ago results from two environmental mechanisms documented through analysis. First, the dark surface pebbles, having absorbed solar heat throughout the day, generate a layer of warm air just above the ground that functions as a buffer against wind, preventing sand from being deposited within the cleared areas. Second, the subsoil contains calcium carbonate that reacts with morning condensation to form a thin surface crust, sealing the pale exposed ground against erosion. Annual rainfall below 25 millimeters and extremely rare high-velocity winds across the plateau remove the remaining variables that would otherwise degrade the figures over geological time.
Form and Features
The Yamagata University and IBM Research study published in PNAS established a formal two-category classification of Nazca geoglyphs based on construction method, scale, depicted motif, and spatial distribution. The first category, line-type geoglyphs, are large-scale figures with an average size of approximately 90 meters, constructed using the outline clearing method, and depicting predominantly wild animals. The hummingbird, the monkey, the condor, the spider, the whale, the dog, the lizard, and the pelican all fall into this category. Line-type geoglyphs are distributed an average of 34 meters from the elaborate network of linear and trapezoidal geometric formations that cross the pampa, placing them in direct spatial relationship with the ceremonial route system. The second category, relief-type geoglyphs, are small-scale figures averaging approximately 9 meters, produced by clearing both the border and certain interior elements, and depicting predominantly human-related subjects. Among the 303 newly confirmed relief-type geoglyphs, 81.6 percent depict humanoid figures, decapitated heads, domesticated camelids, scenes of human-animal interaction, or ceremonial content. Relief-type geoglyphs are positioned an average of 43 meters from ancient informal walking trails that crisscross the pampa, establishing a spatial relationship with pedestrian movement rather than with the formal ceremonial route network.
The 800 straight lines crossing the plateau represent the most numerically dominant element of the Nazca Lines corpus. Some run for 48 kilometers without measurable deviation. These lines do not follow topographic features; they cross ravines, climb hills, and maintain their direction across all surface irregularities. At certain convergence points, documented as ray centers or radial centers by researchers including Anthony Aveni of Colgate University, multiple lines radiate outward from a single hub point in all directions simultaneously. Aveni's 1990 survey documented 62 such ray centers across the pampa. The trapezoidal areas, large cleared geometric zones wider at one end than the other, extend across sections of the plateau at varying scales and are consistently positioned in or near dried riverbeds and seasonal water channels.
The geometric corpus also includes spirals, zigzag formations, triangles, rectangles, and wave-like curves. The spiral is the most frequently recurring geometric element across both the large-format and small-format geoglyphs. Its significance in Nazca ceramic iconography, where spiral forms appear in association with water deity imagery, has been used by researchers to propose a connection between spiral geoglyphs and water-related ritual. Among the animal figures, the spider has attracted particular attention. Astronomer Phyllis Pitluga of the Adler Planetarium, building on work by María Reiche, proposed in the 1990s that the spider's body was designed to align with the star system Orion, with specific limbs corresponding to individual stars. This astronomical interpretation was contested by scholars including Anthony Aveni and Edwin Barnhart, who found the alignment evidence insufficient to support the conclusion with confidence.
Function and Use
No written record by the Nazca people documents the purpose of the lines. All functional interpretations are derived from archaeological evidence, spatial analysis, comparison with other features of Nazca culture, and ethnographic analogy with later Andean traditions. The absence of a confirmed explanation has generated a larger volume of competing theories than any other archaeological site in South America.
The water and fertility hypothesis, advanced most systematically by anthropologist Gary Urton of Harvard University and supported by analysis conducted by the Nasca-Palpa Project formed in 1997, proposes that the lines and trapezoidal areas are spatially organized in relation to the underground water table and seasonal surface water channels of the Nazca drainage system. Many straight lines were found, upon excavation of their endpoints, to terminate at ancient water sources, seasonal streams, or locations where subsurface water was accessible. The trapezoidal clearings are consistently positioned at points along the watercourse network. Urton proposed that the lines mapped the Nazca people's conceptual relationship to water movement across the landscape and served as pilgrimage routes connecting communities to sacred water sources during times of drought.
The walking and procession hypothesis, developed by multiple researchers including David Johnson and supported by the spatial findings of the 2024 PNAS study, proposes that the lines were primarily surfaces to be walked during ritual processions rather than images to be viewed from above. The network of informal trails documented by the Yamagata University survey, consistently positioned in close proximity to small relief-type geoglyphs depicting human and ceremonial subjects, establishes that pedestrian movement across the pampa was a sustained and organized activity. The scale of the geometric formations, particularly the wide trapezoidal areas, is consistent with large-group movement rather than individual passage.
The astronomical calendar hypothesis was the first systematically proposed scholarly interpretation, advanced by American historian Paul Kosok who observed from an airplane in 1941 that one line he was examining appeared to align with the setting sun on the winter solstice. German mathematician and archaeologist María Reiche adopted and expanded this hypothesis across four decades of field work, concluding that the entire complex functioned as an astronomical calendar in which individual lines and figures corresponded to celestial rising and setting points. In 1990, astronomer Gerald Hawkins and archaeoastronomer Anthony Aveni conducted a systematic statistical analysis of the alignment data and concluded that the number of alignments with significant celestial events was no greater than what would be produced by chance given the large number of lines. Their findings did not fully disprove Reiche's hypothesis but established that the astronomical alignment evidence was insufficient to support it as a complete explanatory framework.
The 2024 PNAS study's spatial differentiation between line-type and relief-type geoglyphs has produced the most empirically grounded distinction in function proposed by any peer-reviewed research. Large line-type figures depicting wild animals, positioned along formal ceremonial route networks, were most likely created through coordinated community labor for community-level ritual activities. Small relief-type figures depicting human subjects and ceremonial scenes, positioned along informal walking trails, were most likely made at the individual or small-group level for private or small-scale ritual activities during travel across the pampa. This distinction, if confirmed by subsequent analysis, resolves the longstanding scholarly problem of explaining why a single site contains both monumental communal figures and small intimate compositions through the straightforward explanation that both categories of activity occurred there, independently and simultaneously.
Cultural Context
The Nazca civilization developed on the arid coastal plain of southern Peru from approximately 100 BCE and flourished between 1 and 700 CE before declining and being absorbed into the expanding Wari Empire by approximately 750 CE. Nazca society was organized into local chiefdoms rather than a centralized state, each led by specialist priests who coordinated community labor, directed religious activities, and managed the economic and agricultural systems of their communities. No evidence of a palace, central government building, or administrative archive has been found at any Nazca site, making the Lines the most conspicuous evidence of coordinated communal labor in the entire material record of the civilization.
The principal ceremonial center of Nazca culture was Cahuachi, located in the lower Nazca Valley approximately 6 kilometers from the modern city of Nazca, where the Nazca River passes underground rather than flowing on the surface. The Nazca people interpreted the disappearance of the river into the earth at this point as a sign that the location was sacred, the Quechua term huaca. Cahuachi was not an inhabited city. It was a pilgrimage site consisting of adobe pyramid mounds and open plazas where communities gathered from across the Nazca region at specific times of year for ceremonies, feasting, and burial. Excavations at Cahuachi have recovered large quantities of polychrome pottery, corn, beans, pumpkin, peanuts, textiles, and small amounts of gold and Spondylus shell, consistent with offerings brought by pilgrims. Animal remains confirm that llamas and guinea pigs were sacrificed at the site. The site was established before the primary period of Nazca Lines construction and continued in use throughout it, establishing the ceremonial pilgrimage tradition as the dominant framework of Nazca religious life during the same period the geoglyphs were being made.
Trophy heads, severed human skulls with holes drilled through the forehead, tongues removed and placed in a pouch, and lips sealed with cactus spines, appear as a recurring motif in Nazca ceramic decoration and have been recovered in significant numbers from Cahuachi and other sites. Analysis published by Donald Proulx of the University of Massachusetts established that 85 percent of examined trophy head specimens are males between the ages of 20 and 50. A cache of 48 trophy heads was recovered from Cerro Carapo in the Palpa Valley. DNA analysis published in 2009 established that a significant proportion of trophy heads came from the same population as the people they were buried with rather than from external enemy groups, indicating that at least some trophy heads were produced through ritual sacrifice of community members rather than exclusively through warfare. Among the 303 geoglyphs newly discovered through the 2024 AI survey, a group depicting scenes of human sacrifice including a priest carrying a human head was identified, establishing a direct visual documentation of the trophy head practice within the geoglyph program itself.
Nazca shamans are documented through pottery imagery as practitioners who consumed hallucinogenic substances extracted from the San Pedro cactus, Echinopsis pachanoi, to induce visions and communicate with the spirit world. The Nazca people worshipped nature deities governing agriculture, water, and fertility, including a mythical killer whale, a harvester deity, a spotted cat, the hummingbird, and a serpent. The killer whale and hummingbird figures carved into the desert are among the most precisely identified geoglyphs, their forms matching the specific representations of these deities on Nazca pottery with a consistency that confirms intentional correspondence between the ceramic iconographic program and the geoglyph program.
The civilization was destroyed not by warfare but by environmental collapse. An El Niño event triggered widespread and catastrophic flooding across the Nazca region sometime after 500 CE. Prior deforestation of the Prosopis pallida, a local tree whose root system stabilized the desert soil and whose removal was documented through analysis of sediment cores, had eliminated the landscape's primary erosion control mechanism. The floodwaters, channeled by the destabilized terrain, destroyed agricultural infrastructure and forced abandonment of Cahuachi. The Nazca experienced their environmental collapse as divine abandonment, the withdrawal of the gods whose favor they had sustained through ceremony, sacrifice, and the construction of the geoglyphs. The Wari Empire, expanding from the Ayacucho highlands, absorbed the remaining Nazca population within one to two generations after the flooding.
Discovery and Preservation
Toribio Mejía Xesspe, a Peruvian archaeologist, identified the lines and began the first systematic study of them in 1927 after encountering them on foot during fieldwork in the Nazca Valley. His study was published in 1939. Commercial aviation across the region in the 1930s revealed the full scale of the geoglyphs from the air for the first time. American historian Paul Kosok conducted the first aerial study in 1941. German mathematician and archaeologist María Reiche arrived in Peru in 1932 as a tutor and translator, met Kosok, and dedicated the remainder of her life to studying and physically protecting the Nazca Lines. She lived at the site for decades, personally sweeping individual lines clean of sand accumulation with a broom, and lobbied the Peruvian government continuously for formal protection. The Peruvian Air Force provided periodic aerial survey support at her request. Reiche's advocacy was directly responsible for the establishment of the restricted zone that governs access to the site today. She died in Lima in 1998 at the age of 95 and is buried at the site she spent her life protecting.
The Pan-American Highway, constructed through the plateau before the geoglyphs were fully documented, physically severed the tail of the Lizard geoglyph, which had not yet been identified at the time of road construction. In 2014, Greenpeace activists walked across the pampa adjacent to the Hummingbird figure to place a banner message without wearing the protective footwear required for all researchers entering the restricted zone, causing permanent impressions in the surface soil that are still visible and which the Peruvian Ministry of Culture called irreversible. In early 2018, a truck driver entered the restricted zone on the Pan-American Highway and drove across the pampa, leaving tracks measuring 104 by 328 feet and damaging three geoglyphs.
UNESCO designated the Lines and Geoglyphs of Nasca and Palpa a World Heritage Site in 1994. The Ministry of Culture of Peru administers the restricted access zone through the Dirección Desconcentrada de Cultura de Ica. The 2024 PNAS study by Yamagata University and IBM Research, which required 2,640 ground-truthing labor hours in the field to verify 303 AI-identified geoglyphs, established a documented methodology for AI-assisted archaeological survey that the study authors proposed could be applied to comparable sites worldwide. The same research team's LiDAR survey of the entire Nazca pampa produced three-dimensional terrain models used to map flood pathways across the site, identifying that the Pan-American Highway itself may channel flash flood water directly over certain geoglyphs during extreme rainfall events. Hydrodynamic modeling is now being used to design terrain modifications that could redirect floodwater around the most vulnerable figures before the next El Niño cycle affects the region.
Why It Matters
The Nazca Lines constitute the largest corpus of geoglyphs produced by a single culture in the ancient world, created through sustained coordinated labor across a total area of 450 square kilometers by a society with no centralized state, no palace administration, and no documentary record explaining what they were doing or why. The 2024 PNAS study, which discovered 303 new figures in six months through AI analysis after 100 years of conventional survey had identified only 430, established that the known geoglyph inventory was less than half complete and that the scale of Nazca geoglyph production was substantially larger than any prior scholarship had established. The identification of a spatial and thematic distinction between large line-type geoglyphs positioned along ceremonial routes and small relief-type geoglyphs positioned along informal walking trails provides the first peer-reviewed evidence-based framework for separating the Nazca geoglyph program into two functionally distinct categories operating simultaneously within the same landscape, resolving a century of debate premised on the incorrect assumption that all geoglyphs at the site were produced for a single unified purpose. The geoglyphs discovered through AI analysis depicting scenes of human sacrifice including a priest carrying a human head constitute the first visual documentation of this practice in the geoglyph program itself, extending the archaeological record of the trophy head tradition from ceramic iconography and skeletal assemblages into the monumental landscape marking the Nazca people left on the desert floor.