Here are some of the elements of the Hyperborean mythos that I intend to use in my novel. This is pieced together from Wikipedia, along with some of my own observations and notes about other sources. If you want the full Wikipedia version of the Hyperborea info, it’s here. http://en.wikipedia.org/wiki/
The Greeks thought that Boreas, the North Wind, lived in Thrace, and that therefore Hyperborea was an unspecified region in the northern lands that lay beyond Scythia (Russia). Their land, called Hyperborea or Hyperboria — "beyond the Boreas" — was perfect, with the sun shining twenty-four hours a day, which - if true - suggests a possible location within the Arctic Circle. The Greeks came up with the idea that north countries being cold was due to the cold breath of Boreas, the North Wind. Therefore, should one be able to get "beyond Boreas" one would find a warm and sunny land.
Never the Muse is absent
from their ways: lyres clash and flutes cry
and everywhere maiden choruses whirling.
Neither disease nor bitter old age is mixed
in their sacred blood; far from labor and battle they live.
- Pindar, Tenth Pythian Ode; translated by Richmond Lattimore.
Reaching such exotic lands is never easy; Pindar cautioned:
neither by ship nor on foot would you find
the marvellous road to the assembly of the Hyperboreans.
Along with Thule, Hyperborea was one of several terrae incognitae to the Greeks and Romans, where Pliny and Herodotus, as well as Virgil and Cicero, reported that people lived to the age of one thousand and enjoyed lives of complete happiness. Also, the sun was supposed to rise and set only once a year in Hyperborea; which would place it above or upon the Arctic Circle, or, more generally, in the arctic polar regions.
H.P. Blavatsky, Rene Guenon and Julius Evola all shared the belief in the Hyperborean, polar origins of humankind and a subsequent solidification and devolution. According to these esoterists, Hyperborea was the Golden Age polar center of civilization and spirituality; humankind does not rise from the ape, but progressively devolves into the apelike condition as it strays physically and spiritually from its mystical otherworldly homeland in the Far North, succumbing to the demonic energies of the South Pole, the greatest point of materialization.
In the Hellboy universe, which is one of my greatest inspirations, Hyperborea is a prehistoric kingdom of powerful beings (possibly distinct from humans—I’m not sure that Mignola is ever clear on that) with incredibly advanced magics and technology. They are brought down by corruption from within: in BPRD: The Hollow Earth, it is revealed that some of the Hyperboreans went elsewhere, leaving the corrupt ones behind. These corrupted beings created a slave race of goblin-like creatures, who eventually overthrew their makers, but can still be harmed by the semi-magical Hyperborean blades. (This is also a major theme in Edward Grey: Witchfinder).