NORWAY: Around 1,300 years ago, Vikings grew marijuana—not for smoking, but for versatile hemp, used for making textiles and rope. Pollen from bog samples taken in the 1940s and 1950s and stored in a museum collection were found to contain higher-than-normal concentrations of hemp pollen. It is not known exactly how the hemp was used, as plant fibers don’t preserve well in this setting, but it appears that the plants were laid out in the wet bog to prepare them for processing. —Samir S. Patel