This film presents the history, mythology & folklore that the earth has a hollow realm, a mystical and physical place of great mystery and wonder. The hollow earth theory is represented in the history of many diverse cultures throughout the world. The Avalon of Camelot, the Garden of Eden, Paradise Lost, Shangri-La and Valhalla are names assigned to a mystical and physical place thought by some to house prehistoric animals and plants and by others to hide alien beings bent on conquering the outer Earth.