Short answer: it's a load of crap. It's a stupid idea. It's WRONG!
Long answer+explanation: what you have is a few people grasping at straws to sell ridiculous books, which in turn are filled with even more ridiculous claims. Let's analyze the basic scenario: you have a megalithic structure placed in a certain spot without any discernible purpose. An archeologist (aka a scientist) will now try to discover the purpose behind the structure using previously established knowledge of the religious/cultural customs of the ancient people who lived in the area. If that yields no results, they will look the structure's relative position. It might be a type of calender, or a market place, etc. If that still yields no results, they will (hopefully) collaborate with other archeologists who have studied similar structures in other places. At this point, an answer to the structure's purpose will generally have been found. If there is something new or special to this structure, a new theory on the religious/social/cultural practices of the ancient people of that region may be developed. This is known as science, a systemic approach to problem solving that has exterminated smallpox, landed humans on the moon, and allows a 20-something asshole to post a reply that other people can read.
Conversely, one of those ancient aliens conspiracy theorist will likely claim that humans could not have constructed said structure however many thousands of years ago, or that we even today would not be able to do so (as with the pyramids, which is incidentally a load of shit). He'll then posit that some other force must have intervened, so they'll pick ET, as that claim is just a tiny bit less retarded than claiming that goddidit. They'll then attempt to discern some purpose behind the structure, which will ultimately boil down to "energy" production, or "dimensional gateway," or similar claptrap. Has anything been learned through this idle speculation? Can we apply that conclusion as a basis for a more overarching new theory? Does it even make sense? The answer to all three: hell no!
Look, you can believe whatever you want to, but there are people (like me, and everybody with at least half of a working brain), who will loudly question whether you rode the shortbus back in high school. There is nothing wrong with wanting to know whether or not a claim presented is true or not, but there is something seriously wrong with just buying it without questioning. Here's a good piece of advice: if somebody makes an outlandish claim, chances are good they are retarded or just after some gullible fool's money if any of the following are true: 1) the word "energy" or "dimension" is used without context or further explanation. 2) it relies on "ancient" practices or believes, and is backed up by ancient art/buildings/practices. 3) it fails Occham's razor. 4) there is a claim of suppression of evidence by some shadowy organization, governments, "scientists," the UN, etc. 5) none of the people presenting the claim have real degrees.
I will admit that I occasionally watch that Ancient Aliens show on History. 'course, I drink a shot whenever somebody is laughably wrong, or tries to convince the audience of something a first grader would see through. I yet have to make it through an entire episode while playin' my little drinking game...
Oh, Lord Inglip sayeth: builea sciences.
