There are many accounts of a land of immortality and eternal youth in world myths and legends, as well as shamanic and indigenous spiritual traditions.
Writing in his recent work, Sky Shamans of Mongolia, Kevin Turner tells us that the three worlds or realms of the Mongolian Darkhad shaman don’t consist of a traditional upper, middle, and lower world but are instead overlapping dimensional realities, more in line with a holographic outlook. These places are populated by deities, spirits, and ancestors. In Irish lore it is the land of Tir na Nog where a race of supernatural beings is said to reside, although this otherworld adapts itself to incorporate the afterlife, the Summerland of Wicca, as well as shamanic realms according to other interpretations.
Often these dimensions are seen to be accessed across an ocean, leading many to associate Tir na Nog with the mythical island of Hy-Brasil, an island that was said to rise from the sea every seven years and which was populated by a race of advanced antediluvian beings.