Earliest European Use of Hallucinogenic Plants Found in Bronze Age Andorra

Archaeologists have uncovered evidence of ancient ritual practices at a Bronze Age site in Prats, revealing the earliest known use of hallucinogenic plants in Europe.

The discovery comes from a modest pit excavated in 1999 near the former Trèvol hotel along the historic camí ral in Prats, Canillo parish. Dated to around 1700 BCE during the Middle Bronze Age, the one-metre-deep and one-metre-wide pit contained a stone shelf supporting five ceramic vessels. These held carbonised remains of unprocessed wheat spikes, dairy fats, beer—previously undocumented in Andorran prehistoric sites—and mushrooms wrapped in fern leaves. Most strikingly, analysis identified traces of *Datura stramonium*, or stramonium, a potent hallucinogen known historically as "witches' herb" for inducing tachycardia, hallucinations, delirium, convulsions, or even death in severe cases.

Cristina Yáñez, the archaeologist leading the study, presented these findings at the Jornades d'Història de Canillo on Monday during the session "Secrets soterrats: excavacions arqueològiques a Prats." She noted that stramonium had never appeared in Andorran prehistoric contexts and was rare across Europe, with the only comparable ritual site being the later Bronze Age Hungarian site of Pécs (1350–1150 BCE). The plant, part of the Solanaceae family alongside tobacco, tomatoes, peppers, aubergines, and mandrake, was long thought to originate in the Americas and spread post-1492. The Prats evidence, alongside Pécs, proves it was known and ritually consumed in Europe millennia earlier.

Yáñez described the pit—also called Fossa de Prats or les Olles de Prats—as strategically located in a "sacred landscape" encompassing the Rep forest and pre-Christian sanctuaries like Roc de les Bruixes, contemporary with the pit but unconnected. No human remains or habitation structures were found, ruling out funerary use despite expanded excavations. Instead, she interprets it as a votive ritual site where proto-Andorrans offered cereals, beer, mushrooms, and hallucinogens to enter trance states, communing with deities, spirits, or ancestors.

The pit was nearly destroyed during water pipe installation but preserved after the excavator unearthed it. The Jornades continue today with Quim Valera on power spaces in Canillo parish, and tomorrow with Robert Pastor on Canillo's witches, beliefs, trials, and popular imagery.