No single answer is settled
Nobody knows for certain why the Nazca Lines were made, and the honest summary is that the question is debated. No Nazca writing survives to explain them, because the culture had no known script. Scholars studying the Nazca culture of Peru therefore work from the ground itself, from pottery and textile imagery, from excavation at nearby sites, and from comparison with later Andean practice. The explanation most widely favoured today connects the lines with water, fertility and ritual movement, while the earlier idea that they formed an astronomical calendar has largely lost support in its original form.
These are not entirely rival camps. Many researchers think the lines served more than one purpose, and that different lines may have been made for different reasons over several centuries.
Why water is the central theme
The Nazca region lies in one of the driest parts of the Pacific coast of South America. Rain is rare, and farming depended on a few rivers that often run dry, together with water taken from underground. In such a place, concern about water is not a speculative theme: it shapes daily life.
The evidence usually cited for a water link includes:
- Nazca pots and textiles that show crops, seeds, and creatures associated with water and fertility.
- Lines that point toward, or run between, places where water flows or where springs and rivers meet the plain.
- Ceremonial sites such as Cahuachi, where offerings and gatherings suggest large, organised ritual.
- The way many geoglyphs are drawn in single continuous lines, an arrangement that suits being followed on foot.
The scholar Johan Reinhard developed one influential version of the argument in the 1980s. Drawing on later Andean beliefs, he proposed that the lines were linked with the worship of mountains and water, since in the Andes mountains are traditionally seen as sources of rain and fertility. The comparison is useful, but it uses evidence from later periods, so it remains an interpretation rather than a proof.
Ritual walking paths
A large share of the markings are not pictures at all. They are straight lines, wide cleared bands and trapezoids, some running for kilometres. Many figures also have a single outline that can be followed without crossing itself. Researchers such as Anthony Aveni, who studied the lines closely, noted how many lines radiate from central points. These look like pathways to be walked, perhaps in groups, as part of ceremonies that were repeated over years.
Small offerings found at certain points, and traces of use along some paths, are often cited as signs of walking and ritual use. This fits the way the Nazca animal figures can be traced by foot even where they are too large to see whole from the ground. Under this view the meaning lay in the act of walking and in the offerings made, and not in the design as a picture to be viewed from above.
The puquios and underground water
South of the plateau, the Nazca valleys contain structures called puquios. These are underground channels that tap water and bring it to the surface, with spiral-shaped access openings that can still be seen. Some researchers connect them with the same water-focused world as the lines, while others note that their date is uncertain: some argue for an origin in the Nazca period, and others for later construction. A water-management system and a ritual landscape could easily belong to the same culture, and some scholars see links with other pre-Inca Andean states that also managed scarce water, but the dating needs to be handled carefully.
A related idea, put forward in a 1990s study, suggested that many lines follow underground water and geological faults. That claim has not become the consensus, and it does not explain the animal figures well. It is better treated as one more suggestion that water mattered, not as a full explanation.
The astronomical calendar idea
The earlier explanation came from Paul Kosok, an American historian who visited in 1941. He reportedly saw the sun set almost directly over the end of one line near the winter solstice in the southern hemisphere, and called the plain “the largest astronomy book in the world.” Maria Reiche, whose Maria Reiche survey mapped much of the plain over decades, developed the idea that lines marked solstices and the positions of stars.
Later checks were less encouraging. In the 1960s the astronomer Gerald Hawkins compared line directions with the positions of the sun, moon and bright stars using calculations, and found that the alignments were about what chance would produce, given how many lines there are. Aveni and others reached broadly similar conclusions, though some individual alignments still look plausible. The fair summary is that astronomy may have played a part in timing ceremonies, but that a precise astronomical calendar written across the whole plain is not supported.
How the explanations fit together
A rough way to hold the main ideas in mind:
| Idea | Main support | Main difficulty |
|---|---|---|
| Water and fertility | Desert setting, imagery on pottery, ritual centres | Relies partly on later Andean beliefs |
| Ritual walking paths | Layout of lines and single-stroke figures | Physical traces are limited |
| Astronomical calendar | A few striking solstice alignments | Statistical tests show no strong pattern |
Dating the lines themselves relies on pottery and on radiocarbon dating of associated wood, and the Palpa hillside geoglyphs to the north suggest that the tradition changed over time. The most cautious reading is that the lines were part of Nazca religion, linked to the land, to water and to processions, and that the sky was one element among others. New work may refine this, particularly where excavation links a specific line to a specific period. For now, claims of a single, solved answer should be treated with scepticism.