Merlin, cannabis seeds attached to pottery shards found in Japan have been dated to roughly 10,000 years ago. AdvertisementSupported byScientists Find Ancient Humans Used Weed 2,500 Years Ago, Too Residue found in tombs deep in a Central Asian mountain range suggests that strong cannabis was used in ancient burial rites.ImageDense patches of wild cannabis grow across the mountain foothills of Eurasia from the Caucuses to East Asia. Close to the bodies was a fur-lined leather bag with cannabis seeds, a bronze cauldron filled with stones and the frame of what seems to be an inhalation tent.Dr. He hypothesized that “It was used to facilitate the body communicating with the afterlife, the spirit world.”The study was published in the journal Science Advances. They are separated by rows of black and white stones, the purpose of which is unknown.