Scientists have discovered two pounds of a dried plant that turned out to be the oldest marijuana in the world. Inside one of the Yanghai Tombs excavated in the Gobi Desert, a team of researchers found the cannabis packed into a wooden bowl resting inside a 2,700-year-old grave. It was placed near the head of a blue-eyed, 45-year-old shaman among other objects like bridles and a harp to be used in afterlife.