I get amused when people on shows, like late night talk shows, talk about The Great Pyramid and their crackpot theories about its purpose, as if it were the one and only pyramid in Egypt. If you look you can see the there is pyramid right next to The Great Pyramid that is almost as large, and one that is about half the size then there are several more smaller ones. Look around and you see more small ones.
To Egyptologist the pyramids are not even close to being a mystery. They were tombs. I remember some show on TV long ago where some man spent his life trying to prove that The Great Pyramid was the Old Testament in stone. I don't know how you could say that that section of stones is the 23rd Psalm. That would be particularly remarkable since the Pyramid was built before the Old Testament was written!
Another of the myriad so called theories was that The Great Pyramid is encrypted data. The person did not suggest what the data might be. He didn't realize that it would be undecipherable now because most of the facing stones are gone. In any case if it was data important enough to be encrypted, why did they not build another pyramid later to update their data?
Contrary to what people who have not done their homework may think. The Great Pyramid was not the crowning achievement of Egyptian Architecture. The Egyptians still had two thousand years of history to go after the Pyramid was built.
I remember seeing Erich von Daniken (of ancient astronaut fame) on TV in the 90's (Ithought his theories had been discredited years ago.) on the History Channel saying that it was obvious that aliens made the pyramids because they were beyond the capabilities of humans at the time.
Not only is that an insult to humans, but if aliens built the pyramids then: They travelled billions of light years to reach earth in order to show humans how to build with stone, went through a series of trail and error to figure out how to build them, built the causeway, funarary chapel and other outbuildings as well as the workers housing.
Egyptians built mastaba, a rectangular shelter of stone above the graves of people. A guy named Zoser decided to stack mastaba on top of each other and ended up with the Step Pyramid. Next there was a guy named Sneferu who made a pyramid that is called the Callapsed Pyramid because they made a mistake in the building and it wasn't stable. Next he built a pyramid that was not anchored on solid bedrock was had a slope that was too steep. They had to change the slope at the top, thus it is called the Bent Pyramid. Finally he got it right and built the Red Pyramid.
Khufu (Cheops) was the pharoh who had The Great Pyramid built. Inside is a thing that looks very much like a sarcophagus, where he was originally buried. We don't know exactly how the pyramids were made, but they were materpieces of craftsmanship, not technology. They may have used ramps of sand, or levers. One guy even thinks they might have put cemicircular shaped wood on the stones so they could be rolled. None of these required intervention from Aliens.
In the workman's quarters archelogists have found graffitti. None of which mentions any alien overseers.