Graham Hancock stops short of being an “ancient astronaut theorist,” but does challenge the traditional interpretations of ancient monumental architecture—particularly the great pyramids—with an eye on the esoteric. I particularly like his metaphysical angle, and his matter-of-fact observations, such as the total lack of evidence that the “queen’s” tomb of the Great pyramid was a tomb at all.
If you are a Lovecraft, Howard, Wolfe or Bloch reader you should enjoy Quest for the Lost Civilization. I intend to view it again.