honestly how did they build so massive things in ancient times

what if these where all done by an alien socieity living in our world why all the reason for secret military bases they must be hiding something bigger then weapons and technology could it be that they are hiding another species more intelligent then us

Large slave labor forces, alien tech, or some form of magnetic force lifting that has been lost to the ages.

One man likely discovered (or rediscovered) a form of magnetic lifting in the early 20th century. His name was Ed Leedskalnin and he managed to single handedly cut and manipulate into position large heavy pieces of coral into some strange monument. You can see his work at the site below.

www.coralcastle.com...

Large slave labor forces

That is my bet, and seems to be backed up by ancient art, etc. However, I'd love to know how Coral Castle was built....

I would think that harmonics played a big part. Wasn't Tesla experimenting with sound?