This book takes the reader on a fantastic journey through a wide range of cultures and traditions to examine the phenomenon of ecstatic visionary experiences -- from Sumerian Gilgamesh and the Taoist Immortals to the imaginative fiction of Jorge Luis Borges. The author provides a comprehensive tour of otherworldly journeys common from immemorial times among shamans, magicians, and witches, and illustrates their connection with such modern phenomena as altered states of consciousness, out-of-body experiences, and near death experiences.