I don’t buy the alien theory and I don’t buy the textbook explanation, either. Celestial markers would certainly indicate that the pyramids and the sphinx were built around 12,500 YBP, and that would also adequately explain why there is undeniable water erosion on and all around the sphinx.
Ever notice that ancient monolithic stone cutting is identical in South America and Egypt?
And then there’s Gobekli Tepe, the oldest (provably dated to over 11,000 years old) monolithic site on Earth. It tells of a catastrophe that all but annihilated mankind in a two-part flooding event caused by a fragmented comet. They say it happened about 13,000 YBP (the first impact and flood, which occurred in North America). How do we date this? Celestial alignments…
Every single one of the most ancient religions, along with 10,000+ year old cave paintings from the Hopi Natives, all tell of a flood that destroyed mankind. They also all have tales of a distant past, during some “Golden Age of Mankind” where giant cut stones were used.
Oddly enough, the very first thing the Bible talks about after the events of Noah, is the Tower of Babel, where the Bible emphasizes that man was now building things with fired ceramic bricks and mortar, instead of using cut stone.
And speaking of cut stone versus bricks and mortar, why in the heck would the builders of Machu Picchu go through all that trouble to build stone structures out of (up to) 800 ton cut granite, then turn around and top it off with garbage like this?
So when you take actual history, geology, and astronomy into account, the archeology just doesn’t hold water.
Speaking of water, there are sunken cities all around the world, just like Dwarka exist around the world in places that haven’t been above sea level since the end of the last Ice Age (the Deluge).
So who built all these? To me, it looks like Humans built it, with a form of technology not necessarily higher than ours, but certainly very different (think Tesla’s frequency-tuning theories vs our conventional “blow it up” model of energy production).
We are a species with amnesia, and the remains of what we once were are all around us in plain site.