The use of cannabis goes way, way back. Two thousand and five hundred years ago, a middle-aged prehistoric man died and his body was wrapped in the plant. Archeaologists unearthed his grave recently, finding the ancient cannabis remarkably preserved and offering valuable insight into the modern world's understanding of the plant's historical and cultural significance.

According to a report from the journal Economic Botany by archeaologist Hongen Jiang and his colleagues, the grave was found in the Jiayi cemetery in Turpan, China and approximately 2800-2400 years old. The man -- 35 years old with Caucasian features -- had been arranged carefully on a wooden bed, a report from National Geographic said.

There were 13 nearly whole cannabis plants, which were carefully arranged as what appeared to be a "burial shroud" on the corpse. It lay diagonal to the body, from underneath the pelvis to the head.

Jiang revealed that this extraordinary discovery is the first time that scientists were able to uncover complete cannabis plants from the time period, and it's the first time it was seen used in human burial. It supports the belief that cannabis was commonly used by the people in central Eurasia for ritual and medicine thousands of years ago.

Furthermore, the archaeologists concluded that the plants were local after realizing that they were laid flat on the corpse and therefore must have been fresh at the time of the burial. There were a few that still had flowering heads with immature fruit, suggesting it was harvested in late summer.

Beyond all the facts gleaned from the discovery, the question is why. Why was cannabis there?

Discounting cannabis' use as cloth or food - there were no textiles or practical food source found in the area to support these theories - the researchers believe that this particular cannabis "cache" was produced for its psychoactive resin in the flowering heads of the plants found in the Jiayi grave. This resin may have been inhaled or drank as a ritual or medicine.