Incredible discovery: archaeologists at Tambo Viejo in southern Peru have found sacred coca leaves still caught in the wool of sacrificed Inka llamas, exposing a ritual practice that written colonial accounts never clearly described.
The evidence comes from Structure 4 at Tambo Viejo, an Inka provincial center in Peru’s Acarí Valley. During excavations, researchers uncovered a group of nine young llamas that had been deliberately prepared for sacrifice. The animals were decorated with tassels, their faces were marked with red paint, and their legs were folded and tied beneath their bodies as if they had been placed in a resting position.
What made the deposit extraordinary was what remained in the wool. Coca leaves were still attached to three of the llamas, preserving direct physical evidence that the plant had been placed on or scattered across the animals during the ceremony. The discovery is described in the journal Ñawpa Pacha by archaeologist Lidio M. Valdez of the University of Calgary and colleagues Katrina J. Bettcher and M. Soledad Gutiérrez.
The ritual appears to have been elaborate. After the llamas were arranged, clean river sand was poured over them. Four guinea pigs were then placed above the animals, more sand was added, and a fire was lit before the entire offering was sealed beneath a clay floor. Radiocarbon dating places the ceremony between roughly AD 1450 and 1500.
That sequence matters because coca was far more than an everyday stimulant in the Inka world. Ethnohistorical sources describe the plant as a prestigious and sacred offering associated with deities, ancestors and powerful spirits. In the worldview reconstructed by archaeologists, relationships with those non-human powers were reciprocal: people offered valuable things in hopes of receiving protection, fertility, abundance or political stability in return.
Until now, however, direct archaeological evidence for exactly how coca was used in this kind of state ritual had been scarce. Colonial-era Spanish writers reported that coca could be burned or bundled in offerings. The Tambo Viejo deposit preserves the leaves themselves on sacrificial animals, suggesting that at least some ceremonies included a different practice—one that may have involved scattering or placing leaves directly on the victims.
The discrepancy is important because much written knowledge about Inka religion was recorded after the Spanish conquest, often by outsiders working through translation, interrogation and second-hand testimony. Those accounts are indispensable, but archaeology can test them against physical traces left in the ground. At Tambo Viejo, the surviving leaves preserve a ritual action that textual sources either overlooked or described differently.
The location adds another layer of meaning. Tambo Viejo was established as the Inka expanded into Peru’s southern coast. The sacrificial deposit predates some of the earliest buildings in the excavated area, leading the researchers to suggest that the ceremony may have helped consecrate newly controlled land and appease local spiritual powers before construction or occupation intensified.
That interpretation fits a broader pattern in imperial societies: conquest is rarely only military or administrative. New territory must also be made meaningful. For the Inka, ritual offerings could bind political expansion to sacred geography by acknowledging local forces, ancestors and places as active participants in the new order.
The dry environment of the Acarí Valley made the discovery possible. Plant material is usually fragile, and coca leaves are rarely preserved at highland archaeological sites. Tambo Viejo’s arid conditions protected delicate organic remains that would normally disappear, allowing archaeologists to reconstruct gestures that lasted only moments more than five centuries ago.
The find also changes the emotional texture of the sacrifice. These were not anonymous animals deposited casually. The llamas were decorated, painted, positioned and surrounded by valuable offerings. Coca—one of the most culturally charged plants in the Andes—was integrated into that preparation. The ceremony appears to have transformed the animals into deliberate intermediaries between human communities and a sacred landscape.
It is still important not to generalize one deposit into a single universal “Inka ritual.” The empire covered enormous geographic and cultural diversity, and practices could vary by place, political situation and local tradition. What Tambo Viejo provides is something more precise: direct evidence that coca leaves were physically associated with sacrificed llamas in one carefully staged ceremony.
The discovery belongs to a growing body of archaeology showing how ritual behavior can survive in unexpectedly concrete forms. Templum Dianae recently covered another ancient deposit in which animal remains appear to preserve deliberate ceremonial behavior. At Tambo Viejo, a few fragile leaves now do something similar—revealing a sacred action that written history did not fully preserve.
References
https://doi.org/10.1080/00776297.2026.2719320
https://phys.org/news/2026-09-inka-sacred-coca-sacrificed-llamas.html
https://commons.wikimedia.org/wiki/File:Ritual_andino_con_hoja_de_coca.jpg
