Michael Cremo remains as one of the best enlightened researchers around. Fortunately, he has been on coasttocoastam.com many times to express his research & observations.
http://www.youtube.com/watch?v=koYWznEIV50
pyramids-and-other-mysteries
What if the world has various civilizations & entities? Some of which might live deep underground or even occasionally pop in from other dimensions. Some of them might have ulterior or sinister motives.