Concepts of heaven and hell are among the oldest, most widespread religious beliefs in history. In Western literature, they are frequently embedded in stories of underworld explorations and celestial journeys--stories examining the nature of the universe, life on earth and the existence of the gods. The author analyzes tales of wonder in both ancient and medieval European literature. Other-worldly narratives appeared in literary contexts in the ancient world, including mythology, poetry and philosophical writings. In medieval times, they remained a popular form of literary expression. These stories are primarily religious in nature, describing fantastic worlds filled with miracles and supernatural beings.