Hi, prana --
I've read about the Japanese pyramids before (can't remember the name of the book -- it included ancient sites in China). They also got a nod on TV, I think either Discovery or Travel Channel, one of those "weird places" specials.
I don't know about a conspiracy to cover up these findings -- at least, not an American one. Sometimes science gets sidetracked by 1) lack of government/private funding and/or 2) producers looking for ratings, not hard science. Also, scientists seem very cautious these days about sounding sensationalistic.
For example, archaeologists spent 10 years excavating a Civil War site near my mom's home; only a few people even knew they were working there. They wanted to keep souvenir collectors away and preserve the site's integrity, also funding was an issue.
(BTW, I was able to visit the site before it opened to the public; there were some powerful energies there, but they seem to have dissipated since the crowds started visiting. A little hard to describe -- I'm not a "believer" as you say, but just felt something.)
Sam
There is a great streak of violence in every human being. If it is not channeled and understood, it will break out in war or in madness. ~Sam Peckinpah