Often in my life I have wondered about the great pyramids of Egypt. Whenever I saw photos or watched documentaries about them they seemed like they were out of place, not part of the particular time that they were built.
The long accepted theory was the ancient Egyptians built the pyramids, with a work force of thousands, and 20 or so years of effort. I have always found it hard to believe that the ancient Egyptians constructed them, given the nature of the technology available at that time in history.
To build structures such as the pyramids with such precision would require far more sophisticated tools then the ancients had 4,000 years ago.
Zahi Hawass, the famous Egyptologist and former curator of antiquities has often scoffed at ideas that the pyramids were constructed by extraterrestrials or by a super civilization in ancient history. However the evidence points to the contrary. It seems unlikely with the technology that the ancient Egyptians had, that such structures as the pyramids could have been built in 20 years or