On the dusty Nazca Desert in southern Peru, the ground might seem barren. It’s just stones on pale soil, broken by hills and dry creeks. Yet, from the sky, ancient designs come into view, carved by humans over 2,000 years ago. These Nazca Lines have eroded over time, hiding their secrets from casual walkers.
For decades, archaeologists used planes and cameras to map these intricate patterns, identifying about 430 figures across a vast area of approximately 629 square kilometers. Yet, many more geoglyphs likely remained undiscovered, making a complete inventory feel almost impossible.
But between September 2022 and February 2023, that changed. A team led by archaeologist Masato Sakai at Yamagata University joined forces with IBM Research to harness artificial intelligence (AI) for this task. Instead of examining every image manually, they developed a computer model to highlight areas that looked promising for geoglyphs. Archaeologists would then follow up by exploring these sites on foot.
The AI system was specifically designed to detect earthworks, not common buildings or roads. It used deep learning techniques, initially trained on everyday images and then refined with a limited set of Nazca figures. This posed a challenge, as typical models require vast amounts of data. To overcome this, researchers divided confirmed figures into smaller segments, creating more training samples.
The AI generated a geoglyph probability map, pinpointing 47,410 candidates that might conceal new Nazca figures. This map provided exact locations for field teams to investigate further.
Once the groundwork was laid, experts reviewed high-resolution images captured via drones and aircraft. They refined the candidates to 1,309 potential sites, dedicating about 1,200 hours to digital analysis before stepping foot on the plateau.
Over six months, the team explored 341 of the most promising areas. With the authority of Peruvian officials, they spent another 1,440 hours confirming which shapes were of human origin. This meticulous work uncovered 303 new figurative Nazca geoglyphs, plus 42 geometric designs previously undocumented. Altogether, there are now 683 figures in the Nazca Desert.
Most new finds are “relief-type geoglyphs,” subtle designs made from piles or removals of stones. These average about nine meters long and are typically placed in areas where pedestrians can see them. In contrast, the larger “line-type geoglyphs,” averaging 90 meters, are visible from great distances.
Diverse motifs emerge within these styles. Relief-type figures mainly depict humans and domesticated animals like llamas—about 82% of this category. In contrast, line-type figures showcase wild animals, making up 64% of that group. One eye-catching new discovery features a killer whale holding a knife, echoing imagery found on ancient Nazca pottery.
Interestingly, the new study revealed differing alignments for both styles. Relief-type geoglyphs are closer to winding trails, suggesting they were for local foot traffic. The larger line-type designs, however, connect ceremonial centers, indicating different purposes for each style.
The emerging data highlights how rapidly discoveries can be made. From the 1940s to the early 2000s, about 1.5 figures were identified each year. Thanks to improved technology, the rate surged to nearly 19 a year after 2004. The recent AI-assisted survey achieved an incredible sixteen-fold increase in discoveries within a single season.
Sakai sees the benefit of this technology not as a replacement for fieldwork, but as a tool to enhance it. “AI allows us to target our searches more effectively,” he noted. The AI still points to an additional 968 sites that haven’t been checked, and estimates suggest at least 248 more figures might be real.
This project is pioneering a new era in archaeological research, serving as a model for others around the world. Detailed documentation of their methods in the journal Proceedings of the National Academy of Sciences can guide other researchers in unlocking historical mysteries through AI and modern survey techniques.
As technology continues to evolve, it will be exciting to see what other secrets the Nazca Desert holds, waiting to be discovered beneath the stones.
