The Hollow Earth, also known as Agartha or Agharta, is a realm below the surface of the earth with one central sun at it's core giving eternal light and a fairly balanced temperature. Real or imagined, the belief in a hollow earth is quite controversial and is rarely given the attention and investigational focus a subject such as this would require. The entrance to the hollow earth is typically at one or both of the poles, though other locations such as mountain caves have thought to have lead to magical realms of immortal beings living in paradise. The network of pyramids around the world in different cultures could indicate a common link to a hidden world, and some believe the underground passages and labyrinths could lead into the hollow earth.
The hollow earth is an image of a microcosm, paradise, and a hidden jewel found by looking within one's self. The belief in a central or black sun represents the idea that within everybody and everything exists a seed of perfection (the soul in humans) which can transform the matter into spiritual gold.