Mount Hekla: Iceland's particularly active volcano developed a reputation as a gateway to Hell in the 12th century, after its 1104 eruption. Benedeit's 1120 Anglo-Norman poem Voyage of St. Brendan mentions the volcano as the prison of Judas, the apostle who betrayed Jesus. That reputation continued with further eruptions; after the 1341 eruption, there was a report that people saw birds flying amidst the fire—birds, some thought, that must really be swarming souls. Even in more recent times, He…