Scientists have discovered the use of hallucinogenic drugs by humans 3,000 years ago.
They believe shamans used drugs as part of rituals held at the Es Càrritx cave in Menorca.
The cave was first occupied around 3,600 years ago, and was used as a funeral space until around 2,800 years ago, the researchers said.
The study, published the journal Scientific Reports, found psychoactive substances atropine, scopolamine and ephedrine on hair strands, which had been dyed red.
The scientists believe the substances, likely derived from various plants, were used as part of rituals held at the cave.