The god Cernunnos (detail from the Gundestrup cauldron, 1st century BC) • WIKIMEDIA COMMONS On May 28, 1891, in northern Denmark, not far from the town of Gundestrup, a 22-year-old Dane named Jens Sørensen was mining the Rævemosen bog, when his shovel hit a hard, metallic object:a 69 cm round pi